Ibuprofen-Famotidine (ibuprofen/famotidine)

To minimize the potential risk of adverse cardiovascular and/or GI events, use the lowest possible effective dosage and shortest duration of therapy consistent with treatment goals of the patient. Dosage of ibuprofen must be carefully adjusted according to individual requirements and response, using the lowest possible effective dosage.

Dosage of ibuprofen lysine is expressed in terms of ibuprofen.

In patients with renal impairment, doses and/or frequency of administration of famotidine can be modified in response to the degree of renal impairment. Adverse CNS effects have been reported in patients with moderate or severe renal insufficiency receiving famotidine, and modification of dosage and/or dosing interval may be used to avoid excess accumulation of the drug in such patients. In adults with moderate (creatinine clearances less than 50 mL/minute) or severe (creatinine clearances less than 10 mL/minute) renal impairment, the manufacturer states that dosage of famotidine may be reduced to half the usual dosage or the dosing interval may be prolonged to 36-48 hours as necessary according to the patient's clinical response. Some clinicians have recommended that one-half the usual adult dosage be administered in adults with creatinine clearances of 30-60 mL/minute per 1.48 m2 and that one-fourth the usual adult dosage be administered in those with creatinine clearances less than 30 mL/minute per 1.48 m2.

Based on the comparison of pharmacokinetic parameters of famotidine in adults and children, dosage adjustment also should be considered in children with moderate or severe renal impairment.

Ibuprofen is administered orally or IV. Ibuprofen lysine is administered IV.

Ibuprofen is also commercially available in the following fixed-combination tablets for oral use: ibuprofen and famotidine (Duexis(R)); ibuprofen and hydrocodone bitartrate. See the full prescribing information for administration of each of these combination products.

Ibuprofen is also commercially available in various over-the-counter (OTC) preparations as a single ingredient or in combination with other analgesics (e.g., acetaminophen), antihistamines, or decongestants. See the FDA Orange Book and the manufacturer's Drug Facts for further information.

Ibuprofen is metabolized mainly via cytochrome P-450 (CYP) isoenzyme 2C9-mediated hydroxylation of R- and S-ibuprofen. There is no evidence of enzyme induction.

Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

Agents Affecting Growth Hormone/Macimorelin

SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

MECHANISM OF ACTION: Agents affecting growth hormone may impact the accuracy of the macimorelin diagnostic test.(1)

CLINICAL EFFECTS: Concurrent use of agents affecting growth hormone may impact the accuracy of the macimorelin diagnostic test.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: The US manufacturer of macimorelin states concurrent use with agents affecting growth hormone may impact the accuracy of the macimorelin diagnostic test. Discontinue growth hormone products at least 1 week before administering the macimorelin diagnostic test. Sufficient washout time of drugs affecting growth hormone release prior to administration of macimorelin is recommended.(1) Agents affecting growth hormone include: - Drugs that directly affect the pituitary secretion of growth hormone (e.g. somatostatin, insulin, glucocorticoids, cyclooxygenase inhibitors) - Drugs that may transiently elevate growth hormone concentrations (e.g. clonidine, levodopa, insulin) - Drugs that may blunt the growth hormone response (e.g. muscarinic antagonists, anti-thyroid medications, growth hormone products)

DISCUSSION: Concurrent use of agents affecting growth hormone may impact the accuracy of the macimorelin diagnostic test.(1)

Cyp1a2 Inhibitors/Fezolinetant

SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

MECHANISM OF ACTION: Inhibitors of CYP1A2 may inhibit the metabolism of fezolinetant.(1-4)

CLINICAL EFFECTS: Concurrent use of a CYP1A2 inhibitor may increase levels of and adverse effects from fezolinetant.(1-4)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Recommendations for concurrent use of fezolinetant with CYP1A2 inhibitors differ in different regions. The US manufacturer of fezolinetant states that concurrent use with strong, moderate, and weak CYP1A2 inhibitors is contraindicated.(1) The Australian, Canadian, and UK manufacturers of fezolinetant state that concurrent use with strong and moderate CYP1A2 inhibitors is contraindicated, while weak CYP1A2 inhibitors are not predicted to cause clinically relevant changes in fezolinetant exposure.(2-4)

DISCUSSION: In a study, fluvoxamine, a strong CYP1A2 inhibitor, increased fezolinetant maximum concentration (Cmax) and area-under-curve (AUC) by 80% and 840%, respectively. Mexiletine (400 mg every 8 hours), a moderate CYP1A2 inhibitor, increased fezolinetant Cmax and AUC by 40% and 360%, respectively. Cimetidine (300 mg every 6 hours), a weak CYP1A2 inhibitor, increased fezolinetant Cmax and AUC by 30% and 100%, respectively.(1) Strong CYP1A2 inhibitors linked to this monograph include angelica root, ciprofloxacin, enasidenib, enoxacin, fluvoxamine, and rofecoxib. Moderate CYP1A2 inhibitors linked to this monograph include capmatinib, centanafadine, dipyrone, fexinidazole, genistein, hormonal contraceptives, methoxsalen, mexiletine, osilodrostat, phenylpropanolamine, pipemidic acid, rucaparib, troleandomycin, vemurafenib, and viloxazine. Weak CYP1A2 inhibitors linked to this monograph include acyclovir, allopurinol, artemisinin, belumosudil, caffeine, cannabidiol, cimetidine, curcumin, dan-shen, deferasirox, disulfiram, Echinacea, famotidine, ginseng, norfloxacin, obeticholic acid, parsley, piperine, propafenone, propranolol, ribociclib, simeprevir, thiabendazole, ticlopidine, triclabendazole, valacyclovir, verapamil, and zileuton.(5-7)

H2 Antagonists/Olverembatinib

SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

MECHANISM OF ACTION: The aqueous solubility of olverembatinib is pH dependent. Higher gastric pH leads to lower solubility which may reduce olverembatinib absorption.(1)

CLINICAL EFFECTS: Coadministration of H2 receptor antagonists may reduce the bioavailability of olverembatinib leading to decreased systemic levels and effectiveness.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: The manufacturer of olverembatinib states that concurrent use with H2 receptor antagonists should be avoided.(1)

DISCUSSION: Olverembatinib has pH-dependent solubility.(1)

H2 Antagonists; Proton Pump Inhibit/Posaconazole Suspension

SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

MECHANISM OF ACTION: H2 antagonists and proton pump inhibitors (PPIs) increase the stomach pH, possibly reducing gastrointestinal absorption of posaconazole suspension.

CLINICAL EFFECTS: Concurrent use of H2 antagonists or proton pump inhibitors (PPIs) may result in decreased effectiveness of posaconazole suspension.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Avoid the concurrent use of posaconazole suspension with H2 antagonists or proton pump inhibitors (PPIs).(1) If H2 antagonists or PPI therapy is required, use the tablet formulation or powder mix formulation of posaconazole.

DISCUSSION: Concurrent cimetidine (400 mg twice daily) decreased both posaconazole (200 mg daily) maximum concentration (Cmax) and area-under-curve (AUC) levels by 39%.(1) No significant effects with other H2 blockers have been noted.(1) Esomeprazole (40 mg daily for 3 days) decreased the Cmax and AUC of a single dose of posaconazole suspension (400 mg) by 46% and 32%, respectively.(1) In a study of posaconazole levels in patients with acute myeloid leukemia or myelodysplastic syndrome, use of pantoprazole was associated with decreased posaconazole levels.(3) In a cross-over study in 5 healthy subjects, esomeprazole decreased the Cmax and AUC of posaconazole suspension by 37% and 84%, respectively. Simultaneous intake of Coca-Cola did not completely counteract the effects of esomeprazole.(4) In a study in healthy subjects, esomeprazole decreased the Cmax and AUC of posaconazole suspension by 55% and 49%, respectively. Simultaneous intake of Coca-Cola did not completely counteract the effects of esomeprazole.(5)

H2 Antagonists; Proton Pump Inhibitors/Defactinib

SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

MECHANISM OF ACTION: The aqueous solubility of defactinib is pH dependent. Higher gastric pH leads to lower solubility which may reduce defactinib absorption.(1)

CLINICAL EFFECTS: Coadministration of H2 antagonists or proton pump inhibitors (PPIs) may reduce the bioavailability of defactinib, leading to decreased systemic levels and effectiveness.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: The manufacturer of defactinib states that concurrent use with H2 antagonists or proton pump inhibitors should be avoided.(1) If concurrent use with an acid-reducing agent cannot be avoided, administer defactinib 2 hours before or 2 hours after the administration of a locally acting antacid.(1)

DISCUSSION: In an interaction study, defactinib area-under-the-curve (AUC) decreased by 79% and maximum concentration (Cmax) decreased by 85% following concomitant use of multiple doses of omeprazole 40 mg daily. The AUC and Cmax of N-desmethyl amide (M4), a major metabolite of defactinib, decreased by 83% and 88%, respectively.(1)

H2 Antagonists; Proton Pump Inhibitors/Levoketoconazole

SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

MECHANISM OF ACTION: The aqueous solubility of levoketoconazole is pH dependent. Higher gastric pH leads to lower solubility. H2-receptor antagonists (H2RAs) and proton pump inhibitors (PPIs) increase gastric pH and may decrease the absorption of levoketoconazole.(1)

CLINICAL EFFECTS: Coadministration of H2RAs or PPIs may reduce the bioavailability of levoketoconazole, leading to decreased systemic levels and effectiveness.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Coadministration of levoketoconazole with PPIs and H2RAs should be avoided.(1)

DISCUSSION: Levoketoconazole is very slightly soluble in water but soluble below pH 2. H2RAs and PPIs raise gastric pH and may impair dissolution and absorption of levoketoconazole.(1)

H2 Antagonists; Proton Pump Inhibitors/Nirogacestat

SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

MECHANISM OF ACTION: The aqueous solubility of nirogacestat is pH dependent. Higher gastric pH leads to lower solubility which may reduce nirogacestat absorption.(1)

CLINICAL EFFECTS: Coadministration of proton pump inhibitors (PPIs) or H2 antagonists may reduce the bioavailability of nirogacestat, leading to decreased systemic levels and effectiveness.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Coadministration of nirogacestat with proton pump inhibitors, H2 antagonists, and antacids should be avoided. If coadministration with an acid-reducing agent is unavoidable, take nirogacestat 2 hours before or 2 hours after a locally acting antacid.(1)

DISCUSSION: The solubility of nirogacestat is poor at a pH >= 6.(1) Concomitant use of proton pump inhibitors, H2 antagonists, or antacids are expected to reduce concentrations of nirogacestat.(1)

H2 Antagonists; Proton Pump Inhibitors/Secretin

SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

MECHANISM OF ACTION: H2 antagonists and proton pump inhibitors (PPIs) may result in an incorrect secretin stimulation test result.(1)

CLINICAL EFFECTS: Concurrent use of H2 antagonists and proton pump inhibitors (PPIs) may impact the accuracy of the secretin stimulation test.(1)

PREDISPOSING FACTORS: Patients with alcoholic or other liver disease may be hyperresponsive to stimulation with a secretin stimulation test, masking the presence of coexisting pancreatic disease. Consider additional testing and clinical assessment for diagnosis.(1)

PATIENT MANAGEMENT: The US manufacturer of human secretin states concurrent use of H2 antagonists and proton pump inhibitors (PPIs) at the time of stimulation testing may cause the patient to be hyperresponsive to secretin stimulation and suggest false gastrinoma results. The manufacturer recommends discontinuing H2 antagonists at least 2 days prior to testing. The US manufacturer of vonoprazan recommends stopping vonoprazan at least 4 weeks prior to testing.(2-3) Consult prescribing information for PPIs before administering prior to a secretin stimulation test.(1)

DISCUSSION: Concurrent use of H2 antagonists and proton pump inhibitors (PPIs) may impact the accuracy of the secretin stimulation test.(1)

H2 Antagonists; Proton Pump Inhibitors/Sotorasib

SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

MECHANISM OF ACTION: The aqueous solubility of sotorasib is pH dependent. Higher gastric pH leads to lower solubility which may reduce sotorasib absorption.(1)

CLINICAL EFFECTS: Coadministration of proton pump inhibitors (PPIs) or H2 antagonists may reduce the bioavailability of sotorasib, leading to decreased systemic levels and effectiveness.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Coadministration of sotorasib with proton pump inhibitors, H2 antagonists, and antacids should be avoided. If coadministration with an acid-reducing agent is unavoidable, take sotorasib 4 hours before or 10 hours after a locally acting antacid.(1) The UK manufacturer of sotorasib states if co-administration with an acid-reducing agent (such as a PPI or an H2 antagonist) is required, sotorasib should be taken with an acidic beverage (such as cola). Alternatively, sotorasib should be taken 4 hours before or 10 hours after administration of a local antacid.(2)

DISCUSSION: The solubility of sotorasib in the aqueous media decreases over the range pH 1.2 to 6.8 from 1.3 mg/mL to 0.03 mg/mL. In an interaction study, coadministration of repeat doses of omeprazole with a single dose of sotorasib decreased sotorasib maximum concentration (Cmax) by 65% and area-under-curve (AUC) by 57% under fed conditions, and decreased sotorasib Cmax by 57% and AUC by 42% under fasted conditions. Under fasted conditions, co-administration of repeat doses of omeprazole with a single dose of sotorasib and 240ml of an acidic beverage (non-diet cola) decreased sotorasib Cmax by 32% and AUC by 23%. The UK manufacturer of sotorasib states the clinical relevance of the decreased sotorasib exposure when co-administered with omeprazole and cola is unclear and sotorasib efficacy might be reduced.(2) Coadministration of a single dose of famotidine given 10 hours prior to and 2 hours after a single dose of sotorasib under fed conditions decreased sotorasib Cmax by 35% and AUC by 38%.(1)

H2 Antagonists; Proton Pump Inhibitors/Taletrectinib

SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

MECHANISM OF ACTION: The aqueous solubility of taletrectinib is pH dependent. Higher gastric pH leads to lower solubility which may reduce taletrectinib absorption.(1)

CLINICAL EFFECTS: Coadministration of H2 antagonists or proton pump inhibitors (PPIs) may reduce the bioavailability of taletrectinib, leading to decreased systemic levels and effectiveness.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: The manufacturer of taletrectinib states that concurrent use with H2 antagonists or proton pump inhibitors should be avoided.(1) If concurrent use with an acid-reducing agent cannot be avoided, administer taletrectinib 2 hours before or 2 hours after the administration of a locally acting antacid.(1)

DISCUSSION: In an interaction study, taletrectinib area-under-the-curve (AUC) decreased by 40% and maximum concentration (Cmax) decreased by 65% following concomitant use of omeprazole 40 mg daily.(1)

Nsaid; Aspirin (>300Mg); Salicylat/Ketorolac (Non-Injection)

SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

MECHANISM OF ACTION: Possible additive or synergistic side effects.(1,2)

CLINICAL EFFECTS: Concurrent use of multiple doses of ketorolac with other non-steroidal anti-inflammatory agents (NSAIDs), salicylates or aspirin may result in an increase in NSAID-related side effects such as bleeding or renal impairment.(1-3)

PREDISPOSING FACTORS: Patients with pre-existing renal impairment may be at an increased risk of adverse effects from this interaction. The risk for bleeding episodes may be greater in patients with multiple disease-associated factors (e.g. thrombocytopenia, advanced liver disease). Drug associated risk factors include concurrent use of multiple drugs which inhibit anticoagulant/antiplatelet metabolism and/or have an inherent risk for bleeding (e.g., anticoagulants, antiplatelets, corticosteroids, selective serotonin reuptake inhibitors (SSRIs) or serotonin-norepinephrine reuptake inhibitors (SNRIs). Risk of GI bleed may be increased in patients who are of older age, in poor health status, or who use alcohol or smoke. Risk may also be increased with longer duration of NSAID use and prior history of peptic ulcer disease and/or GI bleeding.

PATIENT MANAGEMENT: Manufacturers of ketorolac state that concurrent use of ketorolac with either other NSAIDs or aspirin is contraindicated.(1,2) If concurrent therapy is deemed medically necessary, monitor patients receiving concurrent therapy for signs of blood loss, including decreased hemoglobin, hematocrit, fecal occult blood, and/or decreased blood pressure and promptly evaluate patients with any symptoms. When applicable, perform agent-specific laboratory tests (e.g. INR, aPTT) to monitor efficacy and safety of anticoagulation. Discontinue anticoagulation in patients with active pathologic bleeding. Conduct periodic monitoring of renal function, especially in patients with renal impairment. Instruct patients to report any signs and symptoms of bleeding, such as unusual bruising; red or black, tarry stools; acute abdominal or joint pain and/or swelling.

DISCUSSION: Based upon similar pharmacodynamic effects and potentially cumulative risks of serious NSAID-related adverse events, manufacturers of ketorolac state the concurrent administration of ketorolac with other NSAIDs or aspirin is contraindicated.(1,2)

Nsaids; Aspirin (>300 Mg); Salicylate/Ketorolac (Injectable)

SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

MECHANISM OF ACTION: Possible additive or synergistic side effects.(1)

CLINICAL EFFECTS: Concurrent use of multiple doses of ketorolac with other non-steroidal anti-inflammatory agents (NSAIDs), salicylates or aspirin may result in an increase in NSAID-related side effects such as bleeding or renal impairment.(1-3)

PREDISPOSING FACTORS: Patients with pre-existing renal impairment may be at an increased risk of adverse effects from this interaction. The risk for bleeding episodes may be greater in patients with multiple disease-associated factors (e.g. thrombocytopenia, advanced liver disease). Drug associated risk factors include concurrent use of multiple drugs which inhibit anticoagulant/antiplatelet metabolism and/or have an inherent risk for bleeding (e.g., anticoagulants, antiplatelets, corticosteroids, selective serotonin reuptake inhibitors (SSRIs) or serotonin-norepinephrine reuptake inhibitors (SNRIs). Risk of GI bleed may be increased in patients who are of older age, in poor health status, or who use alcohol or smoke. Risk may also be increased with longer duration of NSAID use and prior history of peptic ulcer disease and/or GI bleeding.

PATIENT MANAGEMENT: The manufacturer of ketorolac states that concurrent use of ketorolac with either other NSAIDs, salicylates or aspirin is contraindicated.(1) If concurrent therapy is deemed medically necessary, monitor patients receiving concurrent therapy for signs of blood loss, including decreased hemoglobin, hematocrit, fecal occult blood, and/or decreased blood pressure and promptly evaluate patients with any symptoms. When applicable, perform agent-specific laboratory tests (e.g. INR, aPTT) to monitor efficacy and safety of anticoagulation. Discontinue anticoagulation in patients with active pathologic bleeding. Instruct patients to report any signs and symptoms of bleeding, such as unusual bleeding from the gums or nose; unusual bruising; red or black, tarry stools; red, pink or dark brown urine; acute abdominal or joint pain and/or swelling.

DISCUSSION: Manufacturers of ketorolac state that concurrent use of ketorolac with either other NSAIDs, salicylates or aspirin is contraindicated.(1,2) If concurrent therapy is deemed medically necessary, monitor patients receiving concurrent therapy for signs of blood loss, including decreased hemoglobin, hematocrit, fecal occult blood, and/or decreased blood pressure and promptly evaluate patients with any symptoms. Conduct periodic monitoring of renal function, especially in patients with renal impairment.

Selected Nephrotoxic Agents/Bacitracin

SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

MECHANISM OF ACTION: Bacitracin may cause renal failure due to glomerular and tubular necrosis. Concurrent administration of other nephrotoxic agents may result in additive renal toxicity.(1-3)

CLINICAL EFFECTS: Concurrent use of bacitracin with other potentially nephrotoxic agents may result in renal toxicity.(1-3)

PREDISPOSING FACTORS: Dehydration and high-dose bacitracin may predispose to adverse renal effects.(1)

PATIENT MANAGEMENT: Health Canada states that bacitracin is contraindicated in patients with renal impairment, including those taking other nephrotoxic drugs.(1) The Canadian and US manufacturers of bacitracin state that concomitant use of bacitracin with other potentially nephrotoxic agents should be avoided.(2,3)

DISCUSSION: Renal impairment is a major toxicity of bacitracin. Cases of nephrotoxicity have been reported when bacitracin was used off-label.(1-3)

Selected Nephrotoxic Agents/Cidofovir

SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

MECHANISM OF ACTION: Cidofovir is nephrotoxic. Concurrent administration of other nephrotoxic agents may result in additive or synergistic effects on renal function.(1-3)

CLINICAL EFFECTS: Concurrent use of cidofovir with nephrotoxic agents such as adefovir, intravenous aminoglycosides, amphotericin B, foscarnet, intravenous pentamidine, tenofovir, vancomycin, voclosporin and non-steroidal anti-inflammatory agents may result in renal toxicity.(1-3) Other nephrotoxic agents include capreomycin, cisplatin, gallium nitrate, high-dose methotrexate, and streptozocin.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: The Australian,(1) UK,(2) and US(3) manufacturers of cidofovir state that concurrent administration of potentially nephrotoxic agents such as adefovir, intravenous aminoglycosides, amphotericin B, foscarnet, intravenous pentamidine, tenofovir, vancomycin, voclosporin and non-steroidal anti-inflammatory agents may result in renal toxicity.(1-3) Other nephrotoxic agents include capreomycin, cisplatin, gallium nitrate, high-dose methotrexate, and streptozocin. These agents should be discontinued at least 7 days before the administration of cidofovir.

DISCUSSION: The safety of cidofovir has not been studied in patients receiving other known potentially nephrotoxic agents. Renal impairment is the major toxicity of cidofovir.(1-3)

Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

Acetaminophen; Nsaids/Alprostadil

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: Alprostadil is a prostaglandin E1 product used to maintain patency of a patent ductus arteriosus (PDA).(1) Acetaminophen and nonsteroidal anti-inflammatory (NSAID) agents inhibit prostaglandins and may be used for PDA closure in addition to pain/fever management.(2-4)

CLINICAL EFFECTS: Simultaneous administration of acetaminophen or NSAIDs may result in decreased clinical effects from alprostadil, including reduction in PDA.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Avoid concurrent administration of acetaminophen or NSAIDs in patients on alprostadil for maintaining patency of a patent ductus arteriosus (PDA).(1)

DISCUSSION: NSAIDs and acetaminophen are used as management for patent ductus arteriosus (PDA) closure.(2-4) Alprostadil is used to maintain patency of a PDA.(1) In a case report, a 37-week gestational age neonate with cardiac defects required alprostadil therapy for PDA patency. After multiple doses of acetaminophen for pain, an echocardiogram showed reduction of the PDA requiring increased doses of alprostadil. Additional acetaminophen was discontinued. Follow up echocardiogram showed successful reversal of PDA reduction and alprostadil dose was reduced.(5)

Agents That Affect Iodide/Radioactive Iodide

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: Many compounds can affect iodide protein binding and alter iodide pharmacokinetics and pharmacodynamics.(1)

CLINICAL EFFECTS: Compounds that affect iodide pharmacokinetics and pharmacodynamics may impact the effectiveness of radioactive iodide.(1)

PREDISPOSING FACTORS: Compounds that affect iodide pharmacokinetics and pharmacodynamics are expected to have the most impact during therapy using radioactive iodide. Diagnostic procedures would be expected to be impacted less.

PATIENT MANAGEMENT: Discuss the use of agents that affect iodide pharmacokinetics and pharmacodynamics with the patient's oncologist.(1) Because indocyanine green contains sodium iodide, the iodine-binding capacity of thyroid tissue may be reduced for at least one week following administration. Do not perform radioactive iodine uptake studies for at least one week following administration of indocyanine green.(2) The manufacturer of iopamidol states administration may interfere with thyroid uptake of radioactive iodine and decrease therapeutic and diagnostic efficacy. Avoid thyroid therapy or testing for up to 6 weeks post administration of iopamidol.(3)

DISCUSSION: Many agents interact with radioactive iodine. The average duration of effect is: anticoagulants - 1 week antihistamines - 1 week anti-thyroid drugs, e.g: carbimazole, methimazole, propylthiouracil - 3-5 days corticosteroids - 1 week iodide-containing medications, e.g: amiodarone - 1-6 months expectorants - 2 weeks Lugol solution - 3 weeks saturated solution of potassium iodine - 3 weeks vitamins - 10-14 days iodide-containing X-ray contrast agents - up to 1 year lithium - 4 weeks phenylbutazone - 1-2 weeks sulfonamides - 1 week thyroid hormones (natural or synthetic), e.g.: thyroxine - 4 weeks tri-iodothyronine - 2 weeks tolbutamide - 1 week topical iodide - 1-9 months (1)

Agents That Affect Iodide/Sodium Iodide I 131

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: Many compounds can affect iodide protein binding and alter iodide pharmacokinetics and pharmacodynamics.(1,2)

CLINICAL EFFECTS: Compounds that affect iodide pharmacokinetics and pharmacodynamics may impact the effectiveness of radioactive iodide.(1,2)

PREDISPOSING FACTORS: Compounds that affect iodide pharmacokinetics and pharmacodynamics are expected to have the most impact during therapy using radioactive iodide. Diagnostic procedures would be expected to be impacted less.

PATIENT MANAGEMENT: Discuss the use of agents that affect iodide pharmacokinetics and pharmacodynamics with the patient's oncologist.(1,2) Because indocyanine green contains sodium iodide, the iodine-binding capacity of thyroid tissue may be reduced for at least one week following administration. Do not perform radioactive iodine uptake studies for at least one week following administration of indocyanine green.(3) The manufacturer of iopamidol states administration may interfere with thyroid uptake of radioactive iodine and decrease therapeutic and diagnostic efficacy. Avoid thyroid therapy or testing for up to 6 weeks post administration of iopamidol.(4)

DISCUSSION: Many agents interact with radioactive iodine. The average duration of effect is: anticoagulants - 1 week antihistamines - 1 week anti-thyroid drugs, e.g: carbimazole, methimazole, propylthiouracil - 3-5 days corticosteroids - 1 week iodide-containing medications, e.g: amiodarone - 1-6 months expectorants - 2 weeks Lugol solution - 3 weeks saturated solution of potassium iodine - 3 weeks vitamins - 10-14 days iodide-containing X-ray contrast agents - up to 1 year lithium - 4 weeks phenylbutazone - 1-2 weeks sulfonamides - 1 week thyroid hormones (natural or synthetic), e.g.: thyroxine - 4 weeks tri-iodothyronine - 2 weeks tolbutamide - 1 week topical iodide - 1-9 months (1,2)

Anticoagulants; Antiplatelets; Thrombolytics/Caplacizumab

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: Bleeding has been reported with the use of caplacizumab.(1)

CLINICAL EFFECTS: Concurrent use of caplacizumab with anticoagulants, antiplatelets, or thrombolytics may increase the risk of hemorrhage.(1)

PREDISPOSING FACTORS: The risk for bleeding episodes may be greater in patients with disease-associated factors (e.g. hemophilia, coagulation factor deficiencies). Drug associated risk factors include concurrent use of multiple drugs which inhibit anticoagulant/antiplatelet metabolism and/or have an inherent risk for bleeding (e.g. NSAIDs).

PATIENT MANAGEMENT: Avoid the use of caplacizumab with anticoagulants, antiplatelets, and thrombolytics. Interrupt caplacizumab therapy if clinically significant bleeding occurs. Patients may require von Willebrand factor concentrate to rapidly correct hemostasis. If caplacizumab is restarted, closely monitor for signs of bleeding.(1) If concurrent therapy is warranted, monitor patients receiving concurrent therapy for signs of blood loss, including decreased hemoglobin, hematocrit, fecal occult blood, and/or decreased blood pressure and promptly evaluate patients with any symptoms. When applicable, perform agent-specific laboratory tests (e.g. INR, aPTT) to monitor efficacy and safety of anticoagulation. Discontinue anticoagulation in patients with active pathologic bleeding. Instruct patients to report any signs and symptoms of bleeding, such as unusual bleeding from the gums or nose; unusual bruising; red or black, tarry stools; red, pink or dark brown urine; acute abdominal or joint pain and/or swelling. The time of highest risk for a coumarin-type drug interaction is when the precipitant drug is initiated or discontinued. Contact the prescriber before initiating, altering the dose or discontinuing either drug.

DISCUSSION: Bleeding has been reported with caplacizumab. In clinical studies, severe bleeding adverse reactions of epistaxis, gingival bleeding, upper gastrointestinal hemorrhage, and metrorrhagia were each reported in 1% of patients. Overall, bleeding events occurred in approximately 58% of patients on caplacizumab versus 43% of patients on placebo.(1) In post-marketing reports, cases of life-threatening and fatal bleeding were reported with caplacizumab.(1)

Cimetidine; Famotidine/Tizanidine

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: Cimetidine and famotidine may inhibit the metabolism of tizanidine by CYP1A2.(1)

CLINICAL EFFECTS: Concurrent use of cimetidine or famotidine may result in elevated levels of and effects from tizanidine, including hypotension, bradycardia, drowsiness, sedation, and decreased psychomotor function.

PREDISPOSING FACTORS: The risk of anticholinergic toxicities including cognitive decline, delirium, falls and fractures is increased in geriatric patients using more than one medicine with anticholinergic properties.(2)

PATIENT MANAGEMENT: The US manufacturer of tizanidine states that concurrent use of tizanidine with inhibitors of CYP1A2, such as cimetidine or famotidine, should be avoided. If concurrent use is warranted, tizanidine should be initiated with 2 mg dose and increased in 2-4 mg steps daily based on patient response to therapy.(1) If adverse reactions such as hypotension, bradycardia, or excessive drowsiness occur, reduce or discontinue tizanidine therapy.(1)

DISCUSSION: In a study in 10 healthy subjects, concurrent fluvoxamine, another inhibitor of CYP1A2, increased tizanidine maximum concentration (Cmax), area-under-curve (AUC), and half-life (T1/2) by 12-fold, 33-fold, and 3-fold, respectively. Significant decreases in blood pressure and increases in drowsiness and psychomotor impairment occurred.(1) In a study in 10 healthy subjects, concurrent ciprofloxacin, another inhibitor of CYP1A2, increase tizanidine Cmax and AUC by 7-fold and 10-fold, respectively. Significant decreases in blood pressure and and increases in drowsiness and psychomotor impairment occurred.(1)

H2 Antagonists/Dasatinib; Pazopanib

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: The solubility of dasatinib(1) and pazopanib(2) is pH dependent. Changes in gastric pH from H2 antagonists may decrease the absorption of dasatinib(1) and pazopanib.(2)

CLINICAL EFFECTS: Use of H2 antagonists may result in decreased levels and effectiveness of dasatinib(1) and pazopanib.(2)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Avoid the use of H2-antagonists and proton pump inhibitors (PPIs) in patients receiving treatment with dasatinib(1) or pazopanib.(2) Consider the use of short-acting antacids in these patients.(1) If antacids are used, separate the administration times by at least two hours for dasatinib(1) and several hours for pazopanib.(2) The manufacturer of Phyrago states that it can be administered with gastric acid reducing agents. Administration times should be separated with antacids.(3)

DISCUSSION: In a study in 24 healthy subjects, administration of a single dose of dasatinib (50 mg) 10 hours after famotidine decreased dasatinib area-under-curve (AUC) and maximum concentration (Cmax) by 61% and 63%, respectively.(1) In a study in 14 healthy subjects, administration of a single dose of dasatinib (100 mg) 22 hours after omeprazole (40 mg at steady state) decreased dasatinib AUC and Cmax by 43% and 42%, respectively.(1) In a study in 24 healthy subjects, simultaneous administration of dasatinib (50 mg) with aluminum hydroxide/magnesium hydroxide (30 ml) decreased dasatinib AUC and Cmax by 55% and 58%, respectively. In the same subjects, administration of the antacid 2 hours before dasatinib decreased dasatinib Cmax by 26%, but had no effect on dasatinib AUC.(1) In a study in 13 patients, esomeprazole (40 mg daily for 5 days) decreased the Cmax and AUC of pazopanib (400 mg daily) by 42% and 40%, respectively, when compared to the administration of pazopanib alone.(2) Phyrago is not sensitive to increased gastric pH due to its polymer formulation. No clinically significant pharmacokinetic changes were seen with concurrent administration of Phyrago with omeprazole (proton pump inhibitor) or famotidine (H2 receptor antagonist).(3)

H2 Antagonists/Ziftomenib

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: The aqueous solubility of ziftomenib is pH dependent. Higher gastric pH leads to lower solubility which may reduce ziftomenib absorption.(1)

CLINICAL EFFECTS: Coadministration of H2 receptor antagonists may reduce the bioavailability of ziftomenib, leading to decreased systemic levels and effectiveness.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: The manufacturer of ziftomenib states that concurrent use with H2 antagonists should be avoided.(1) If concurrent use cannot be avoided, administer ziftomenib 2 hours before or 10 hours after the administration of an H2 receptor antagonist.(1)

DISCUSSION: The impact of H2 receptor antagonists on the pharmacokinetics of ziftomenib has not been investigated in clinical studies. In an interaction study, coadministration of proton pump inhibitors (PPIs) decreased ziftomenib area-under-the-curve (AUC) by 53% and maximum concentration (Cmax) by 70%.(1)

H2 Antagonists;Proton Pump Inhibitors/Methylphenidate Xr-Odt

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: The solubility of methylphenidate extended release orally disintegrating tablets (XR-ODT) is pH-dependent. At elevated pH, methylphenidate may be released from the tablets more quickly, resulting in increased absorption.(1)

CLINICAL EFFECTS: Coadministration of H2 antagonists or proton pump inhibitors (PPIs) may result in an altered pharmacokinetic profile of methylphenidate XR-ODT, which may change the effectiveness and/or adverse effects of methylphenidate XR-ODT.(1,2)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Coadministration of methylphenidate XR-ODT with H2 antagonists or PPIs is not recommended.(1,2)

DISCUSSION: In in vitro studies, when media pH was increased from 1.2 to 6.8, percentage release of methylphenidate from the XR-ODT tablet was increased by 67% at 0.5 hours, and by 93% at 2.5 hours. The increased dissolution of methylphenidate at higher pH may result in increased drug absorption and change the concentration-time profile of methylphenidate, which is correlated with pharmacological effect.(1)

Long Acting Antacids; H2s;Ppis/Selected Cephalosporins

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: Absorption of oral cefpodoxime or cefuroxime may be reduced in patients receiving concomitant treatment with acid reducing agents.(1-5)

CLINICAL EFFECTS: Antibiotic efficacy against organisms with a high minimum inhibitory concentration (MIC) to cefpodoxime or cefuroxime could be decreased.

PREDISPOSING FACTORS: Taking cefpodoxime or cefuroxime on an empty stomach magnifies this effect.

PATIENT MANAGEMENT: If possible, avoid the use of H2 antagonists and proton pump inhibitors(PPIs) in patients taking cefpodoxime or cefuroxime. If concurrent therapy is needed with antacids, H2 antagonists, or PPIs, administer cefpodoxime or cefuroxime after eating to maximize oral absorption. Some vitamin preparations may contain sufficient quantities of calcium and/or magnesium salts with antacid properties to interact as well.

DISCUSSION: In a study of ten subjects, administration of cefpodoxime after single dose famotidine 40 mg decreased both maximum concentration (Cmax) and area-under-curve (AUC) by approximately 40 percent compared with administration of cefpodoxime on an empty stomach.(3) In a study of 17 subjects, administration of cefpodoxime after single dose ranitidine 150 mg decreased Cmax and AUC by approximately 40 percent compared with administration of cefpodoxime on an empty stomach.(4) In a study performed prior to the introduction of PPIs, administration of ranitidine 300 mg and sodium bicarbonate followed by cefuroxime taken on a empty stomach lowered both Cmax and AUC of cefuroxime by approximately 40 per cent compared with administration of cefuroxime alone on an empty stomach. Postprandial administration of cefuroxime in subjects taking ranitidine was similar to that of subjects taking cefuroxime on an empty stomach.(5)

Non-Steroidal Anti-Inflammatory Drugs/Inotersen

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: Inotersen causes reductions in platelet count that may result in sudden and unpredictable thrombocytopenia. Inotersen can also cause glomerulonephritis and renal toxicity. NSAIDs can impair thromboxane-dependent platelet aggregation by blocking the formation of thromboxane A2. Concurrent administration with NSAIDs may also result in additive or synergistic effects on renal function.(1)

CLINICAL EFFECTS: Concurrent use of inotersen with NSAIDs may result in additive or synergistic effects, including fatal and non-fatal intracranial hemorrhage, or renal toxicity.(1)

PREDISPOSING FACTORS: The risk for bleeding episodes may also be greater in patients greater than 60 years or have a prior history of major bleeding events. Drug associated risk factors include concurrent use of multiple drugs which inhibit anticoagulant/antiplatelet metabolism and/or have an inherent risk for bleeding. Patients with pre-existing renal impairment.

PATIENT MANAGEMENT: Inotersen should be administered with caution in patients receiving NSAIDs. If concurrent therapy is warranted, monitor patients receiving concurrent therapy for signs of blood loss, including decreased hemoglobin, hematocrit, fecal occult blood, and/or decreased blood pressure and promptly evaluate patients with any symptoms. Monitor platelet count frequently. If platelet count is less than 50, stop inotersen treatment and consider discontinuation of NSAID. Monitor for signs and symptoms of thrombocytopenia; such as, unusual or prolonged bleeding (petechiae, easy bruising, hematoma, subconjunctival bleeding, gingival bleeding, epistaxis, hemoptysis, irregular or heavier than normal menstrual bleeding, hematemesis, hematuria, hematochezia, melena), neck stiffness, or atypical severe headache. Monitor renal function closely.

DISCUSSION: In a clinical study, platelet counts below 100 occurred in 25% of inotersen-treated patients, compared with 2% of patients on placebo. Platelet counts below 75 occurred in 14% of inotersen-treated patients, compared to no patients on placebo. In study 1 and its extension study, 39% of inotersen-treated patients with a baseline platelet count below 200 had a nadir platelet count below 75, compared to 6% of patients with baseline platelet counts 200 or higher. Three inotersen-treated patients (3%) had sudden severe thrombocytopenia (platelet count below 25). One patient experienced a fatal intracranial hemorrhage.(1) The safety of inotersen has not been studied in patients receiving other known potentially nephrotoxic agents.(1) Inotersen is only available through a Tegsedi REMS program because of the risk of severe thrombocytopenia and the risk of glomerulonephritis.(1)

Nsaids/Methotrexate; Pralatrexate

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: The exact mechanism is unknown. NSAID-induced inhibition of prostaglandin synthesis may decrease renal perfusion rate and therefore inhibit methotrexate and pralatrexate clearance. NSAIDs may also compete for renal secretion with methotrexate and pralatrexate. Since methotrexate is not extensively protein bound, displacement of methotrexate by NSAIDs is unlikely to have altered methotrexate kinetics.

CLINICAL EFFECTS: Increased levels of methotrexate and pralatrexate, with increased effects, leading to increased risk of severe neurotoxicity, stomatitis, and myelosuppression, including neutropenia.

PREDISPOSING FACTORS: Risk factors for methotrexate toxicity include: - High-dose oncology regimens - Impaired renal function, ascites, or pleural effusions

PATIENT MANAGEMENT: Avoid the use of NSAIDs with high dose methotrexate therapy.(1) If both drugs must be given, monitor methotrexate levels and patient response carefully. Consider extending leucovorin rescue duration. Use caution when administering NSAIDs with low dose methotrexate therapy. (1) Administration of NSAIDs with pralatrexate requires close monitoring for toxicity.(2)

DISCUSSION: A retrospective review documented four cases of methotrexate toxicity during concurrent administration of ketoprofen and methotrexate in 36 patients. Three cases were fatalities.(3) In contrast, a four-way cross-over study in ten subjects found no effect on methotrexate oral or renal clearance by ketoprofen, piroxicam, or flurbiprofen.(4) In a study in 19 subjects, the concurrent administration of methotrexate and piroxicam resulted in a decrease in methotrexate maximum concentration (Cmax) but no other changes in methotrexate kinetics.(5) Another three-way cross-over study in six patients showed no effect by flurbiprofen or ibuprofen on methotrexate kinetics.(6) In contrast, administration of ibuprofen to nine patients resulted in a 39% decrease in methotrexate total clearance and a 40% decrease in methotrexate renal clearance.(7) Information on naproxen is also conflicting. In another arm of the earlier study (7), the administration of naproxen in nine patients decreased methotrexate total clearance by 22%, but had no significant effects on methotrexate renal clearance. In another study in nine subjects, methotrexate altered naproxen kinetics by greater than 30% in six subjects, although these changes were not statistically significant. Naproxen altered methotrexate kinetics by greater than 30% in four subjects, although these changes were also not statistically significant.(8) In contrast, the administration of naproxen with methotrexate in 15 subjects showed no significant effects on methotrexate oral or renal clearance.(9) A study in 19 subjects found that the concurrent administration of etodolac and methotrexate decreased methotrexate Cmax and increased methotrexate mean residence time. There were no changes in methotrexate clearance or area-under-curve (AUC) and no toxicity was observed.(10) A study in 12 patients showed no significant effects of sulindac on methotrexate kinetics unless one patient who had low baseline clearance of methotrexate was excluded from analysis.(11) A study in seven children examined the effects of the children's usual NSAID on methotrexate kinetics. NSAIDs were naproxen, tolmetin, and indomethacin. Methotrexate half-life increased during NSAID administration. There were no significant changes in methotrexate clearance, AUC or volume of distribution. There was inter-subject variably in response. In six of seven patients, NSAID administration increased methotrexate AUC 19-140%.(12) Case reports have documented an interaction between methotrexate and phenylbutazone (13), indomethacin (14), flurbiprofen (15), and naproxen (16,17); however, one naproxen report (16) is complicated by the fact that the patient took 27.5 mg methotrexate in one week instead of 2.5 mg three times weekly. Because of the conflicting data and wide patient variability, caution is warranted during concurrent administration of methotrexate and any NSAID.

Nsaids/Selected Anticoagulants (Vit K Antagonists)

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: The exact mechanism is unknown. Some NSAIDs may displace anticoagulants from plasma protein binding sites. NSAIDs also have the potential to produce gastrointestinal ulceration and bleeding. Some NSAIDs may impair platelet function and prolong bleeding times.

CLINICAL EFFECTS: Concurrent use of anticoagulants and NSAIDs may increase the risk for bleeding.

PREDISPOSING FACTORS: Bleeding risk may be increased in patients with renal impairment and in patients older than 75 years. The risk for bleeding episodes may be greater in patients with multiple disease-associated factors (e.g. thrombocytopenia, advanced liver disease). Drug associated risk factors include concurrent use of multiple drugs which inhibit anticoagulant/antiplatelet metabolism and/or have an inherent risk for bleeding (e.g., other anticoagulants, antiplatelets, corticosteroids, selective serotonin reuptake inhibitors (SSRIs) or serotonin-norepinephrine reuptake inhibitors (SNRIs). Risk of GI bleed may be increased in patients who are of older age, in poor health status, or who use alcohol or smoke. Risk may also be increased with longer duration of NSAID use and prior history of peptic ulcer disease and/or GI bleeding.

PATIENT MANAGEMENT: If concurrent therapy with anticoagulants and NSAIDs is warranted, patients should be closely monitored for signs of blood loss, including decreased hemoglobin and/or hematocrit, fecal occult blood, and/or decreased blood pressure and promptly evaluate patients with any symptoms. When applicable, perform agent-specific laboratory test (e.g. INR, aPTT) to monitor efficacy and safety of anticoagulation. Discontinue anticoagulation in patients with active pathologic bleeding. Instruct patients to report any signs and symptoms of bleeding, such as unusual bleeding from the gums or nose; unusual bruising; red or black, tarry stools; red, pink or dark brown urine; acute abdominal or joint pain and/or swelling. The time of highest risk for a coumarin-type drug interaction is when the precipitant drug is initiated or discontinued. Contact the prescriber before initiating, altering the dose or discontinuing either drug.

DISCUSSION: The effects of NSAIDs on the hypoprothrombinemic response to anticoagulants appears to vary between patients as well as with different NSAIDs. Documentation is frequently contradictory - while studies have shown several NSAIDs to have no effect on the pharmacokinetics of warfarin, case reports have documented increased effects with and without bleeding when these same NSAIDs were administered concurrently with warfarin. While celecoxib has been shown not to affect platelet aggregation or bleeding times and had no effects on the anticoagulant effect of warfarin in healthy subjects, increased prothrombin times and bleeding episodes, some of which were fatal, have been reported, predominantly in the elderly, in patients receiving concurrent therapy with celecoxib and warfarin. Rofecoxib has been shown to increase prothrombin times in subjects who received concurrent warfarin therapy. A post hoc analysis of nonselective NSAIDs in the RE-LY study (compared dabigatran 150 and 110 mg twice daily with warfarin in atrial fibrillation) assessed clinical outcomes by comparing nonselective NSAID use (at least once during trial) with no NSAID use in 2279 patients. The use of NSAIDs was associated an increased risk of major bleeding (hazard ratio (HR) 1.68), gastrointestinal major bleeding (HR 1.81), stroke or systemic embolism (HR 1.50), and hospitalization (HR 1.64).(22) A self-controlled case study of 1,622 oral anticoagulant-precipitant drug pairs were reviewed and found 14% of drug pairs were associated with a statistically significant elevated risk of thromboembolism. Concurrent use of warfarin and sulindac resulted in a ratio of rate ratios (RR) (95% CI) of 3.7 (1.79-7.62); warfarin and etodolac ratio of RR 2.61 (1.6-4.25); warfarin and ibuprofen ratio of RR 1.94 (1.5-2.5); warfarin and naproxen ratio of RR 1.72 (1.35-2.19); warfarin and indomethacin ratio of RR 1.62 (1.03-2.55); warfarin and diclofenac ratio of RR 1.43 (1.07-1.92; warfarin and celecoxib ratio of RR 1.24 (1.02-1.53); and warfarin and meloxicam ratio of RR 1.23 (1.02-1.47).(23) In a nationwide cohort study, patients were evaluated for thromboembolic cardiovascular and clinically relevant bleeding events with concurrent antithrombotic and ongoing NSAID treatment. A total of 108,232 patients were followed for a mean of 2.3 +/- 1.8 years after diagnosis of myocardial infarction. Concomitant NSAID treatment significantly increased the risk for cardiovascular events (hazard ratio (HR) 6.96; 95% CI 6.24 - 6.77; p<0.001) and bleeding events (HR 4.08; 95% CI 3.51 - 4.73; p<0.001) compared to no NSAID treatment. NSAIDs were further evaluated and revealed the use of celecoxib (HR: 4.65; 95% CI: 3.17 to 6.82; p < 0.001, and 3.44; 95% CI: 2.20 to 5.39; p < 0.001, respectively) and meloxicam (HR: 3.03; 95% CI: 1.68 to 5.47; p < 0.001, and 2.80; 95% CI: 1.40 to 5.60; p < 0.001, respectively) had the lowest risk for cardiovascular and bleeding events, receptively. A large systematic review was performed on 72 warfarin drug-drug interactions studies that reported on bleeding, thromboembolic events, or death. Most studies were retrospective cohorts. A meta-analysis of 8 of those studies found a higher rate of clinically significant bleeding in patients on warfarin and NSAIDs (OR=1.83; 95% CI 1.29-2.59). Increased bleeding risk was seen in subgroup analyses with non-selective NSAIDs (OR=1.86; 95% CI 1.10-3.17) and COX-2 inhibitors (OR=1.81; 95% CI 1.3-2.52).(24) If concurrent therapy with anticoagulants and NSAIDs is warranted, it would be prudent to monitor patients closely for increased anticoagulant effects.

Nsaids; Aspirin (> 100 Mg); Salicylates/Mifamurtide

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: High-dose NSAIDs or salicylates may block the macrophage activating effect of mifamurtide.(1)

CLINICAL EFFECTS: Concurrent use of high-dose NSAIDs or salicylates may decrease the effectiveness of mifamurtide.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: The UK manufacturer of mifamurtide states that concurrent use with high-dose NSAIDs or salicylates is contraindicated.(1)

DISCUSSION: In vitro studies have shown that high-dose NSAIDs or salicylates can block the macrophage activating effect of mifamurtide.(1)

Nsaids; Salicylates/Dabigatran

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: Dabigatran is a direct thrombin inhibitor and when taken with agents that effect platelet aggregation and/or other clotting factors increased bleeding episodes can occur.(1,2)

CLINICAL EFFECTS: Concurrent use of dabigatran with NSAIDs or salicylates may result in additive or synergistic effects resulting in unwanted bleeding episodes.(1)

PREDISPOSING FACTORS: Factors associated with an increased risk for bleeding include renal impairment, concomitant use of P-glycoprotein inhibitors, patient older than 74 years, coexisting conditions (e.g. recent trauma, thrombocytopenia, advanced liver disease), use of drugs associated with bleeding risk (e.g. other anticoagulants, antiplatelets, corticosteroids, selective serotonin reuptake inhibitors (SSRIs) or serotonin-norepinephrine reuptake inhibitors (SNRIs)), and patient weight less than 50 kg. (1-3) Risk of GI bleed may be increased in patients who are of older age, in poor health status, who use alcohol or smoke, with longer duration of NSAID use, and with prior history of peptic ulcer disease and/or GI bleeding.

PATIENT MANAGEMENT: Monitor patients receiving concurrent therapy for signs of blood loss and promptly evaluate patients with any symptoms. Discontinue dabigatran in patients with active pathological bleeding.(1) If concurrent therapy is warranted, monitor patients receiving concurrent therapy for signs of blood loss, including decreased hemoglobin, hematocrit, fecal occult blood, and/or decreased blood pressure and promptly evaluate patients with any symptoms. When applicable, perform agent-specific laboratory test (e.g. INR, aPTT) to monitor efficacy and safety of anticoagulation. Discontinue anticoagulation in patients with active pathologic bleeding. Instruct patients to report any signs and symptoms of bleeding, such as unusual bleeding from the gums or nose; unusual bruising; red or black, tarry stools; red, pink or dark brown urine; acute abdominal or joint pain and/or swelling.

DISCUSSION: Dabigatran is a direct thrombin inhibitor and when taken with agents that effect platelet aggregation and/or other clotting factors increased bleeding episodes can occur.(1,2) A post hoc analysis of nonselective NSAIDs in the RE-LY study (compared dabigatran 150 and 110 mg twice daily with warfarin in atrial fibrillation) assessed clinical outcomes by comparing nonselective NSAID use (at least once during trial) with no NSAID use in 2279 patients. The use of NSAIDs was associated an increased risk of major bleeding (hazard ratio (HR) 1.68), gastrointestinal major bleeding (HR 1.81), stroke or systemic embolism (HR 1.50), and hospitalization (HR 1.64).(22)

Nsaids; Salicylates/Selected Immunosuppressants

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: Cyclosporine increases the production of prostaglandin E2 and I2. Prostaglandin E2 has been shown to prevent cyclosporine -induced renal toxicity in animals. NSAIDS and salicylates may increase cyclosporine-induced renal toxicity by blocking the formation of prostaglandins. Concurrent use of everolimus, sirolimus or tacrolimus with NSAIDs or salicylates may result in additive nephrotoxicity.

CLINICAL EFFECTS: Concurrent administration of cyclosporine, everolimus, sirolimus, or tacrolimus and a NSAID or salicylate may result in a decrease in renal function, with or without an alteration in immunosuppressant levels.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: If possible, avoid the concurrent use of NSAIDs or salicylates in patients maintained on cyclosporine, everolimus, sirolimus, or tacrolimus. If concurrent therapy is warranted, patients should be monitored for a decrease in renal function. The NSAID or salicylate may need to be discontinued.

DISCUSSION: A decrease in renal function has been reported with concurrent cyclosporine and diclofenac, sulindac, mefenamic acid, ketoprofen, piroxicam, and naproxen. Decreasing the cyclosporine dose without discontinuing the NSAID does not appear to improve renal function. The use of agents which decrease renal function concurrently with everolimus, sirolimus or tacrolimus should be approached with caution. An observational study of 63 inpatient encounters for 57 transplant patients evaluated concurrent use between calcineurin inhibitor (CNI) therapy and NSAID use. Patients were matched to 126 transplant patients on CNI therapy without NSAID use. Patients who received at least one dose of NSAID had a 12.2% rate of treatment emergent acute kidney injury (AKI). The relative risk ratio for AKI in patient exposed to NSAID therapy was 2.20 (95% CI 0.74-6.54). An increase in 48 hour post NSAID exposure serum creatinine above baseline was documented in 65.9% of patients compared to 46% in the non NSAID group (p=0.016). Multivariate analysis revealed changes in serum creatinine at 48 hours after admission were independently associated with age (p=0.008) and NSAID use (p=0.026).(12)

Nsaids; Salicylates/Selected Platelet Aggregation Inhibitors

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: Abciximab, cangrelor, cilostazol, clopidogrel, dipyridamole, eptifibatide, prasugrel, ticagrelor, vorapaxar and NSAIDs or salicylates inhibit platelet aggregation.

CLINICAL EFFECTS: Concurrent use of platelet aggregation inhibitors and NSAIDs or salicylates may increase the risk of bleeding.

PREDISPOSING FACTORS: The risk for bleeding episodes may be greater in patients with multiple disease-associated factors (e.g. thrombocytopenia, advanced liver disease). Drug associated risk factors include concurrent use of multiple drugs which inhibit anticoagulant/antiplatelet metabolism and/or have an inherent risk for bleeding (e.g., anticoagulants, other antiplatelets, corticosteroids, selective serotonin reuptake inhibitors (SSRIs) or serotonin-norepinephrine reuptake inhibitors (SNRIs). Risk of GI bleed may be increased in patients who are of older age, in poor health status, or who use alcohol or smoke. Risk may also be increased with longer duration of NSAID use and prior history of peptic ulcer disease and/or GI bleeding. Risk increases as the number of risk factors increases.

PATIENT MANAGEMENT: Use caution when administering platelet aggregation inhibitors with NSAIDs or salicylates.(1-5) It would be prudent to monitor patients more closely during concurrent therapy and to use the lowest NSAID or salicylate dose possible. If concurrent therapy is warranted, monitor patients for signs of blood loss, including decreased hemoglobin and/or hematocrit, fecal occult blood, and/or decreased blood pressure and promptly evaluate patients with any symptoms. When applicable, perform agent-specific laboratory test (e.g. INR, aPTT) to monitor efficacy and safety of anticoagulation. Discontinue anticoagulation in patients with active pathologic bleeding. Instruct patients to report any signs and symptoms of bleeding, such as unusual bleeding from the gums or nose; unusual bruising; red or black, tarry stools; red, pink or dark brown urine; acute abdominal or joint pain and/or swelling. The 2010 ACCF/ACG/AHA Consensus guidelines recommend the use of proton pump inhibitors (PPIs) in patients with multiple risk factors for GI bleeding who require antiplatelet therapy. However, esomeprazole and omeprazole should be avoided with clopidogrel as they are expected to reduce the effectiveness of clopidogrel. Use of other PPIs should be approached with caution, as they may reduce the effectiveness of clopidogrel.

DISCUSSION: Because of the increased risk of bleeding, caution is warranted when using this combination. In a nationwide cohort study, patients were evaluated for thromboembolic cardiovascular and clinically relevant bleeding events with concurrent antithrombotic and ongoing NSAID treatment. A total of 108,232 patients were followed for a mean of 2.3 +/- 1.8 years after diagnosis of myocardial infarction. Concomitant NSAID treatment significantly increased the risk for cardiovascular events (hazard ratio (HR) 6.96; 95% CI 6.24 - 6.77; p<0.001) and bleeding events (HR 4.08; 95% CI 3.51 - 4.73; p<0.001) compared to no NSAID treatment. NSAIDs were further evaluated and revealed the use of celecoxib (HR: 4.65; 95% CI: 3.17 to 6.82; p < 0.001, and 3.44; 95% CI: 2.20 to 5.39; p < 0.001, respectively) and meloxicam (HR: 3.03; 95% CI: 1.68 to 5.47; p < 0.001, and 2.80; 95% CI: 1.40 to 5.60; p < 0.001, respectively) had the lowest risk for cardiovascular and bleeding events, receptively.

Nsaids; Salicylates/Sodium Phosphate Bowel Cleanser

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: Bowel cleansing with sodium phosphate causes dehydration, decreased intravascular volume and hyperphosphatemia, which increases phosphate levels in the renal tubules. Abnormally high levels of calcium and phosphate in the renal tubules may precipitate out, resulting in renal injury.(1)

CLINICAL EFFECTS: Use of sodium phosphate for bowel cleansing in patients maintained on nonsteroidal anti-inflammatory drugs (NSAIDs) may increase the risk of acute phosphate nephropathy, which is an acute kidney injury associated with deposits of calcium phosphate crystal in the renal tubules that may result in permanent renal function impairment. Acute phosphate nephropathy presents as acute kidney injury with minimal proteinuria and a bland urine sediment.(2) Use of oral sodium phosphate products at laxative doses has not been associated with acute kidney injury.(3)

PREDISPOSING FACTORS: Patients who may be at an increased risk of acute phosphate nephropathy include those who are over age 55; are hypovolemic or have decreased intravascular volume; have baseline kidney disease, bowel obstruction, or active colitis; and who are using medications that affect renal perfusion or function (such as diuretics, ACE inhibitors, angiotension receptor blockers [ARBs]), and NSAIDs.(2)

PATIENT MANAGEMENT: If possible, use an alternative agent for bowel cleansing.(1) Use sodium phosphate products with caution in patients taking medications that affect kidney function or perfusion, such as ACE inhibitors or ARBs. Obtain baseline and post-procedure labs (electrolytes, calcium, phosphate, BUN, creatinine, and [in smaller, frail individuals] glomerular filtration rate). Instruct patients to drink sufficient quantities of clear fluids before, during, and after bowel cleansing and to avoid other laxatives that contain sodium phosphate. Consider hospitalization and intravenous hydration during bowel cleansing to support frail patients who may be unable to drink an appropriate volume of fluid or who may be without assistance at home.(2) Use of an electrolyte solution for rehydration may decrease the risk of acute phosphate nephropathy.(4,5)

DISCUSSION: Since May 2006, the FDA has received 20 reports of acute phosphate nephropathy associated with the use of Osmo Prep. Concomitant medications included ACE inhibitors or ARBs (11), diuretics (6), and NSAIDs (4).(2) In a retrospective review of colonoscopy patients, simultaneous use of ACE inhibitors or ARBs significantly increased the risk of acute kidney injury from oral sodium phosphate. Diuretic use was also a risk factor.(6) In a case series study of 21 cases of acute phosphate nephropathy in patients who had used oral sodium phosphate, 14 patients received an ACE inhibitor or ARB, 4 used a diuretic, and 3 used an NSAID.(7) Cases have also been reported with rectal products.(8)

Nsaids;Salicylates/Apixaban;Betrixaban;Edoxaban;Rivaroxaban

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: Concurrent use of apixaban(1-4), betrixaban(7), edoxaban(5), or rivaroxaban(6) and nonsteroidal antiinflammatory agents (NSAIDs) or salicylates may result in additive increased risk of bleeding.

CLINICAL EFFECTS: Concurrent use of apixaban(1), betrixaban(7), edoxaban(5), or rivaroxaban(2) with NSAIDs or salicylates may result in unwanted bleeding episodes.

PREDISPOSING FACTORS: Bleeding risk may be increased in patients with renal impairment and in patients older than 75 years. The risk for bleeding episodes may be greater in patients with multiple disease-associated factors (e.g. thrombocytopenia, advanced liver disease). Drug associated risk factors include concurrent use of multiple drugs which inhibit anticoagulant/antiplatelet metabolism and/or have an inherent risk for bleeding (e.g., other anticoagulants, antiplatelets, corticosteroids, selective serotonin reuptake inhibitors (SSRIs) or serotonin-norepinephrine reuptake inhibitors (SNRIs). Risk of GI bleed may be increased in patients who are of older age, in poor health status, or who use alcohol or smoke. Risk may also be increased with longer duration of NSAID use and prior history of peptic ulcer disease and/or GI bleeding.

PATIENT MANAGEMENT: Approach concurrent therapy with apixaban(1-4), betrixaban(7), edoxaban(5), or rivaroxaban(6) with caution. Monitor patients receiving concurrent therapy for signs of blood loss, including decreased hemoglobin, hematocrit, fecal occult blood, and/or decreased blood pressure and promptly evaluate patients with any symptoms. When applicable, perform agent-specific laboratory test (e.g. INR, aPTT) to monitor efficacy and safety of anticoagulation. Discontinue anticoagulation in patients with active pathologic bleeding. Instruct patients to report any signs and symptoms of bleeding, such as unusual bleeding from the gums or nose; unusual bruising; red or black, tarry stools; red, pink or dark brown urine; acute abdominal or joint pain and/or swelling.

DISCUSSION: In a study, naproxen (500 mg) increased apixaban (10 mg) area-under-curve (AUC) and maximum concentration (Cmax) by 1.5-fold an 1.6-fold, respectively, with corresponding increases in clotting tests. There were no changes in the effect of naproxen on arachidonic acid-induced platelet aggregation, no clinically relevant changes in bleeding times, or naproxen pharmacokinetics.(1) In a single dose study, there were no pharmacokinetic or pharmacodynamic interactions between rivaroxaban and naproxen.(6) Although effects seen in the above studies were limited, NSAIDs are known to increase bleeding and may further increase the risk of bleeding with these agents.(1-6) In edoxaban clinical studies, concomitant use of low-dose aspirin (less than or equal to 100 mg/day) or thienopyridines, and NSAIDs was permitted and resulted in increased rates of clinically relevant bleeding.(5) In a study of 34 healthy subjects administered edoxaban 60 mg daily and naproxen 500 mg daily, bleeding time increased by 2.08-fold from baseline on the combination, compared to a 1.23-fold increase with naproxen alone and 1.7-fold increase on edoxaban alone.(8) A self-controlled case study of 1,622 oral anticoagulant-precipitant drug pairs were reviewed and found 14% of drug pairs were associated with a statistically significant elevated risk of thromboembolism. Concurrent use of apixaban and ibuprofen resulted in a ratio of rate ratios (RR) (95% CI) of 5.16 (3.0-8.85); apixaban and celecoxib ratio of RR 1.8 (1.06-3.06); rivaroxaban and etodolac ratio of RR 2.47 (1.18-4.22); rivaroxaban and naproxen ratio of RR 1.89 (1.12-1.43); and rivaroxaban and ibuprofen ratio of RR 1.68 (1.29-4.44).(9)

Selected H2 Antagonists/Infigratinib; Selpercatinib

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: The solubility of infigratinib and selpercatinib is pH dependent. Changes in gastric pH from H2 antagonists may decrease the absorption of infigratinib and selpercatinib.(1,2)

CLINICAL EFFECTS: Use of H2 antagonists may result in decreased levels and effectiveness of infigratinib and selpercatinib.(1,2)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Avoid the use of H2 antagonists, proton pump inhibitors, and locally-acting antacids in patients receiving treatment with infigratinib or selpercatinib. If coadministration with H2 antagonists cannot be avoided, take infigratinib or selpercatinib at least 2 hours before or 10 hours after the H2 antagonist.(1,2) If the H2 antagonist is replaced with an antacid, take infigratinib or selpercatinib 2 hours before or 2 hours after the antacid.(1,2) If the H2 antagonist is replaced with a proton pump inhibitor, take selpercatinib with food.(2) Avoid taking proton pump inhibitors with infigratinib.(1)

DISCUSSION: Infigratinib is practically insoluble at pH 6.8.(1) In a study, ranitidine given 10 hours before and 2 hours after selpercatinib did not have a clinically significant effect on selpercatinib pharmacokinetics.(2)

Selected Nephrotoxic Agents/Colistimethate

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: Colistimethate can cause nephrotoxicity.(1,2) Concurrent administration of other nephrotoxic agents may result in an increased risk of nephrotoxicity.(1) It is suspected that cephalothin interferes with the excretion of colistimethate resulting in enhanced nephrotoxicity.(2,3)

CLINICAL EFFECTS: Concurrent use of colistimethate with other nephrotoxic agents may result in additive nephrotoxic effects.

PREDISPOSING FACTORS: Factors predisposing to nephrotoxicity include higher cumulative doses of colistimethate, longer treatment duration, hypovolemia, and critical illness.

PATIENT MANAGEMENT: Concurrent use of potentially nephrotoxic agents with colistimethate should be avoided.(1,2) If concurrent use is necessary, it should be undertaken with great caution.(1)

DISCUSSION: In a case control study of 42 patients on intravenous colistimethate sodium, NSAIDs were identified as an independent risk factor for nephrotoxicity (OR 40.105, p=0.044).(4) In 4 case reports, patients developed elevated serum creatinine and blood urea nitrogen following concurrent colistimethate and cephalothin (3 patients) or when colistimethate followed cephalothin therapy (1 patient).(3) A literature review found that individual nephrotoxic agents, including aminoglycosides, vancomycin, amphotericin, IV contrast, diuretics, ACE inhibitors, ARBs, NSAIDs, and calcineurin inhibitors, were not consistently associated with additive nephrotoxicity when used with colistimethate. However, when multiple agents (at least 2 additional potential nephrotoxins) were used concurrently, there was a significant correlation to colistimethate nephrotoxicity.(5)

Selected Nephrotoxic Agents/Foscarnet

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: Foscarnet is nephrotoxic. Concurrent administration of other nephrotoxic agents may result in additive or synergistic effects on renal function.(1) Concurrent intravenous pentamidine may also result in hypocalcemia.(1)

CLINICAL EFFECTS: Concurrent use of foscarnet with nephrotoxic agents such as acyclovir, adefovir, intravenous aminoglycosides, amphotericin B, cyclosporine, methotrexate, non-steroidal anti-inflammatory agents, intravenous pentamidine, tacrolimus, tenofovir, vancomycin and voclosporin may result in renal toxicity.(1) Other nephrotoxic agents include capreomycin, cisplatin, gallium nitrate, high-dose methotrexate, and streptozocin.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: The US manufacturer of foscarnet state that concurrent administration of potentially nephrotoxic agents such as acyclovir, intravenous aminoglycosides, amphotericin B, cyclosporine, methotrexate, tacrolimus, and intravenous pentamidine should be avoided.(1) Other nephrotoxic agents include adefovir, capreomycin, cisplatin, gallium nitrate, high-dose methotrexate, non-steroidal anti-inflammatory agents, streptozocin, tenofovir, vancomycin and voclosporin. If concurrent therapy is warranted, monitor renal function closely. In patients receiving concurrent foscarnet and pentamidine, also monitor serum calcium levels and instruct patients to report severe muscle spasms, mental/mood changes, and/or seizures.(1)

DISCUSSION: The safety of foscarnet has not been studied in patients receiving other known potentially nephrotoxic agents. Renal impairment is the major toxicity of foscarnet.(1)

Selected Nsaids; Aspirin (>325 Mg)/Pemetrexed

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: NSAIDs may decrease the clearance of pemetrexed.(1) This decreased clearance may be the result of chronic renal toxicity from NSAIDs or NSAIDs may compete with pemetrexed for tubular secretion.(2)

CLINICAL EFFECTS: Concurrent use of pemetrexed and NSAIDs may result in elevated levels of and toxicity from pemetrexed, including myelosuppression, neutropenia, renal toxicity, and gastrointestinal toxicity.(1)

PREDISPOSING FACTORS: This interaction is expected to be more severe in patients with mild to moderate renal insufficiency (creatinine clearance (CrCl) of 45 ml/min to 79 ml/min) and/or patients taking long acting NSAIDs. (1)

PATIENT MANAGEMENT: In patients with normal renal function (CrCl equal to or greater than 80 ml/min), ibuprofen (400 mg 4 times daily) can be administered with pemetrexed. Aspirin in low to moderate doses (325 mg every 6 hours) does not affect the pharmacokinetics of pemetrexed.(1) In patients with mild to moderate renal insufficiency (CrCl from 45 ml/min to 79 ml/min), NSAIDs with short half-lives should be avoided for 2 days before, the day of, and 2 days after pemetrexed administration. Ibuprofen should be administered with caution in these patients.(1) NSAIDs and salicylates with long half-lives should be avoided for at least 5 days before, the day of, and 2 days following pemetrexed administration in all patients.(1,2) If NSAIDs are required, patients should be monitored for pemetrexed toxicity, especially myelosuppression, renal toxicity, and gastrointestinal toxicity.(1)

DISCUSSION: In patients with normal renal function, ibuprofen (400 mg 4 times daily) decreased the clearance of pemetrexed by 20% and increased its area-under-curve (AUC) by 20%.(1) In a Phase I clinical trial, two patients receiving high dose pemetrexed therapy experienced severe toxicity, both were receiving a NSAID. Following these reports, all patients were required to stop aspirin or other NSAIDs 2 days before and not resume these agents until 2 days after pemetrexed.(2) In two randomized, controlled cross-over trials, 27 cancer patients with a creatinine clearance (CrCl) less than or equal to 60 ml/min received pemetrexed (500 mg/m2) infusion on Day 1 of a 21-day cycle and either aspirin 325 mg or ibuprofen 400 mg orally every 6 hours starting 2 days before pemetrexed administration. Coadministration of aspirin did not affect pemetrexed pharmacokinetics. Ibuprofen decreased the clearance of pemetrexed by 16%, increased its maximum concentration (Cmax) by 15%, and increased the AUC by 20%.(3) Aspirin products linked to this monograph are single ingredient aspirin products with greater than 325 mg strength, and aspirin combination products (e.g. opioid-aspirin or cough/cold/allergy products) with a reasonable likelihood of a total daily aspirin dose > or = 1,300 mg per day.

Moderate Interaction: Assess the risk to the patient and take action as needed.

Agents Affecting Gastric Ph/Itraconazole; Ketoconazole

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Antacids, buffers in didanosine products, H2 antagonists, and proton-pump inhibitors increase the stomach pH. Quinapril tablets may contain a high percentage of magnesium. Since some orally administered azole antifungal agents require an acidic medium for optimal absorption, agents may decrease the absorption of azole antifungal agents.

CLINICAL EFFECTS: Simultaneous administration of an antacid, buffered didanosine, a H2 antagonist, or a proton-pump inhibitor may result in decreased therapeutic effects of the azole antifungal.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: If the concurrent administration of these two agents cannot be avoided, consider administering two capsules of glutamic acid hydrochloride 15 minutes before administering the antifungal and separate the administration times of the antifungal and the agent affecting gastric pH by at least two hours.

DISCUSSION: Itraconazole, ketoconazole, and posaconazole require an acidic medium for predictable dissolution and absorption decreases as pH increases and proton pump inhibitors are expected to decrease their absorption.(1-4) In a study in 11 healthy subjects, omeprazole (40 mg daily) decreased the maximum concentration (Cmax) and area-under-curve (AUC) of itraconazole (200 mg single dose) by 66% and 64%, respectively.(5) In a study in 15 healthy subjects, omeprazole (40 mg daily) had no effect on the pharmacokinetics of itraconazole solution.(6) In a study in 9 healthy subjects, omeprazole (60 mg) decreased the AUC of ketoconazole (200 mg single dose) by 83.4% compared to control (ketoconazole alone). Administration of Coca-Cola (240 ml) with ketoconazole and omeprazole raised ketoconazole AUC to 65% of control values.(7) Omeprazole has been shown to have no significant effect on the absorption of fluconazole(8) or voriconazole.(9) Case reports and in-vivo studies have documented significant decreases in ketoconazole levels during concurrent therapy with H-2 antagonists, including cimetidine and ranitidine. Concurrent administration of itraconazole and famotidine resulted in a significant decrease in itraconazole levels, but no significant changes in famotidine levels. An interaction should be expected to occur between both ketoconazole or itraconazole and the other H-2 antagonists.(10-14) In randomized, open-labeled, cross-over study in 12 healthy subjects, simultaneous administration of an antacid decreased the area-under-curve (AUC) and maximum concentration (Cmax) of a single dose of itraconazole (200 mg) by 66% and 70%, respectively. Time to Cmax (Tmax) increased by 70%.(15) This interaction has also been reported in a case report.(16) In a study in 3 subjects, simultaneous administration of a combination aluminum hydroxide/magnesium hydroxide (30 ml) decreased the AUC of a single dose of ketoconazole (200 mg) by 41%.(172) In a case report, a patient receiving concurrent ketoconazole with aluminum hydroxide, cimetidine, and sodium bicarbonate did not respond to therapy until cimetidine was discontinued and the administration time of aluminum hydroxide and cimetidine was changed to 2 hours after ketoconazole. In a follow-up study in 2 subjects, concurrent cimetidine and sodium hydroxide lowered ketoconazole levels.(18) In a study in 14 subjects, simultaneous administration of aluminum hydroxide/magnesium hydroxide (20 ml, 1800 mg/1200 mg) had no significant effects on fluconazole pharmacokinetics.(3) In a randomized, open-label, cross-over study in 6 subjects, simultaneous administration of itraconazole with buffered didanosine tablets resulted in undetectable levels of itraconazole.(19) In a randomized cross-over study in 12 HIV-positive subjects, administration of buffered didanosine tablets 2 hours after ketoconazole had no effects on ketoconazole levels.(20) In a randomized, cross-over, open-label study in 24 healthy subjects, simultaneous administration of enteric-coated didanosine had no effect on ketoconazole pharmacokinetics.(21) One or more of the drug pairs linked to this monograph have been included in a list of interactions that could be considered for classification as "non-interruptive" in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology.

Agents With Hyponatremia Risk/Desmopressin

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Carbamazepine, chlorpromazine, lamotrigine, NSAIDs, opioids, SSRIs, thiazide diuretics, and/or tricyclic antidepressants increase the risk of hyponatremia.(1-3)

CLINICAL EFFECTS: Concurrent use may increase the risk of hyponatremia with desmopressin.(1-3)

PREDISPOSING FACTORS: Predisposing factors for hyponatremia include: polydipsia, renal impairment (eGFR < 50 ml/min/1.73m2), illnesses that can cause fluid/electrolyte imbalances, age >=65, medications that cause water retention and/or increase the risk of hyponatremia (glucocorticoids, loop diuretics).

PATIENT MANAGEMENT: The concurrent use of agents with a risk of hyponatremia with desmopressin may increase the risk of hyponatremia. If concurrent use is deemed medically necessary, make sure serum sodium levels are normal before beginning therapy and consider using the desmopressin nasal 0.83 mcg dose. Consider measuring serum sodium levels more frequently than the recommended intervals of: within 7 days of concurrent therapy initiation, one month after concurrent therapy initiation and periodically during treatment. Counsel patients to report symptoms of hyponatremia, which may include: headache, nausea/vomiting, feeling restless, fatigue, drowsiness, dizziness, muscle cramps, changes in mental state (confusion, decreased awareness/alertness), seizures, coma, and trouble breathing. Counsel patients to limit the amount of fluids they drink in the evening and night-time and to stop taking desmopressin if they develop a stomach/intestinal virus with nausea/vomiting or any nose problems (blockage, stuffy/runny nose, drainage).(1)

DISCUSSION: In clinical trials of desmopressin for the treatment of nocturia, 4 of 5 patients who developed severe hyponatremia (serum sodium <= 125 mmol/L) were taking systemic or inhaled glucocorticoids. Three of these patients were also taking NSAIDs and one was receiving a thiazide diuretic.(2) Drugs associated with hyponatremia may increase the risk, including loop diuretics, carbamazepine, chlorpromazine, glucocorticoids, lamotrigine, NSAIDs, opioids, SSRIs, thiazide diuretics, and/or tricyclic antidepressants.(1,3-4)

Antacids; H2 Antagonists/Ledipasvir; Velpatasvir

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: The aqueous solubility of ledipasvir and velpatasvir is pH dependent. Higher gastric pH leads to lower solubility which may reduce ledipasvir and velpatasvir's absorption.(1-3)

CLINICAL EFFECTS: Administration of antacids and H2 antagonists may reduce the bioavailability of ledipasvir and velpatasvir, leading to decreased systemic levels and effectiveness.(1-3)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: In order to assure systemic absorption and maximal effectiveness from use of this Hepatitis C treatment, counsel patient to separate products containing ledipasvir or velpatasvir from antacid administration by 4 hours.(1-3) H2 antagonists may be administered simultaneously or 12 hours apart from products containing ledipasvir or velpatasvir at a dose that does not exceed doses comparable to famotidine 40 mg twice daily (or a total daily dose comparable to famotidine 80 mg).(1-3) Some vitamin preparations may contain sufficient quantities of calcium and/or magnesium salts with antacid properties to interact as well.

DISCUSSION: In an interaction study, famotidine 40 mg, given with or 12 hours after a ledipasvir-sofosbuvir dose did not have significant effects on ledipasvir-sofosbuvir exposure.(1) In an interaction study, famotidine 40 mg, given with or 12 hours prior to a velpatasvir-sofosbuvir dose did not have a significant effect on velpatasvir-sofosbuvir exposure.(2) In an interaction study, famotidine (dosage not stated) did not have a significant effect on the pharmacokinetic of sofosbuvir, velpatasvir, or voxilaprevir.(3)

Antacids; H2 Antagonists/Rilpivirine

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Rilpivirine requires an acidic medium for absorption. Antacid or H2 antagonist induced decrease in gastric pH may result in a decrease in rilpivirine absorption.(1)

CLINICAL EFFECTS: Simultaneous administration of an antacid or a H2 antagonist may result in decreased levels and effectiveness of rilpivirine, as well as the development of resistance.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: In patients maintained on rilpivirine, administer antacids at least 2 hours before or 4 hours after rilpivirine.(1) In patients maintained on rilpivirine, administer H2 antagonists at least 12 hours before or 4 hours after rilpivirine.(1) Concurrent use of proton pump inhibitors with rilpivirine is contraindicated.(1) Some vitamin preparations may contain sufficient quantities of calcium and/or magnesium salts with antacid properties to interact as well.

DISCUSSION: In a study in 16 subjects, omeprazole (20 mg daily) decreased the maximum concentration (Cmax), area-under-curve (AUC), and minimum concentration (Cmin) of rilpivirine (150 mg daily) by 40%, 40%, and 33%, respectively. The Cmax and AUC of omeprazole decreased by 14% and 14%, respectively.(1) In a study in 24 subjects, famotidine (40 mg single dose) administered 12 hours before a single dose of rilpivirine (150 mg) had no significant effect on rilpivirine Cmax or AUC.(1) In a study in 23 subjects, famotidine (40 mg single dose) administered 2 hours before a single dose of rilpivirine (150 mg) decreased the rilpivirine Cmax and AUC by 85% and 76%, respectively.(1) In a study in 24 subjects, famotidine (40 mg single dose) administered 4 hours after a single dose of rilpivirine (150 mg) increased the rilpivirine Cmax and AUC by 21% and 13%, respectively.(1)

Antacids; Selected H2 Antagonists/Acalabrutinib Capsules

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Acalabrutinib capsules solubility decreases with increasing pH. Antacid or H2 antagonist induced increase in gastric pH may result in a decrease in acalabrutinib capsules absorption.(1)

CLINICAL EFFECTS: Simultaneous administration of an antacid or a H2 antagonist may result in decreased levels and effectiveness of acalabrutinib capsules.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Separate administration of acalabrutinib capsules and antacids by at least 2 hours.(1) In patients on acalabrutinib capsules, administer acalabrutinib capsules at least 2 hours before taking H2 antagonists.(1) Concurrent use of proton pump inhibitors with acalabrutinib capsules is not recommended.(1) Some vitamin preparations may contain sufficient quantities of calcium and/or magnesium salts with antacid properties to interact as well. Acalabrutinib tablets are not affected by coadministration with H2 antagonists or antacids, and may be used concurrently.(1)

DISCUSSION: In a study in healthy subjects, coadministration with an antacid (calcium carbonate 1 gram) decreased area-under-curve (AUC) of acalabrutinib capsules by 53%. Coadministration with a proton pump inhibitor (omeprazole 40 mg for 5 days) decreased AUC of acalabrutinib capsules by 43%.(1)

Anticoagulants; Antiplatelets/Fruquintinib; Surufatinib

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Bleeding has been reported with the use of fruquintinib and surufatinib.(1,2)

CLINICAL EFFECTS: Concurrent use of fruquintinib or surufatinib with either anticoagulants or antiplatelets may increase the risk of hemorrhage.(1,2)

PREDISPOSING FACTORS: The risk for bleeding episodes may be greater in patients with disease-associated factors (e.g. thrombocytopenia). Drug associated risk factors include concurrent use of multiple drugs which inhibit anticoagulant/antiplatelet metabolism and/or have an inherent risk for bleeding (e.g. NSAIDs).

PATIENT MANAGEMENT: Patients receiving concurrent therapy with fruquintinib and anticoagulants and/or antiplatelets should be closely monitored for changes in platelet count or in International Normalized Ratio (INR). If a serious bleeding event occurs, the manufacturer recommends permanent discontinuation of fruquintinib.(1) Patients receiving concurrent therapy with surufatinib and anticoagulants and/or antiplatelets should be closely monitored for changes in platelet count or in INR.If a serious bleeding event occurs, the manufacturer recommends permanent discontinuation of surufatinib.(2) If concurrent therapy is warranted, monitor patients receiving concurrent therapy for signs of blood loss, including decreased hemoglobin, hematocrit, fecal occult blood, and/or decreased blood pressure and promptly evaluate patients with any symptoms. When applicable, perform agent-specific laboratory tests (e.g. INR, aPTT) to monitor efficacy and safety of anticoagulation. Discontinue anticoagulation in patients with active pathologic bleeding. Instruct patients to report any signs and symptoms of bleeding, such as unusual bleeding from the gums or nose; unusual bruising; red or black, tarry stools; red, pink or dark brown urine; acute abdominal or joint pain and/or swelling. The time of highest risk for a coumarin-type drug interaction is when the precipitant drug is initiated or discontinued. Contact the prescriber before initiating, altering the dose or discontinuing either drug.

DISCUSSION: Bleeding has been reported with fruquintinib in three randomized, double-blinded, placebo-controlled clinical trials. The incidence of grade 1 and grade 2 bleeding events was 28.2%, including gastrointestinal bleeding (10.9%), hematuria (10.6%), and epistaxis (7.5%). The incidence of grade 3 or higher bleeding events was 2.1% and included gastrointestinal bleeding (1.6%) and hemoptysis (0.5%).(1) Bleeding has been reported with surufatinib in clinical trials. Grade 1 and 2 bleeding events included gastrointestinal bleeding, blood in the urine, and gum bleeding. The incidence of grade 3 or greater bleeding events was 4.5%, including gastrointestinal hemorrhage (1.9%), and cerebral hemorrhage (1.1%). Fatalities due to bleeding were reported in 0.3% of patients. The incidence of permanent discontinuation due to bleeding was 2.6% and the incidence of suspension of surufatinib due to bleeding was 3.8%.(2)

Anticoagulants; Antiplatelets/Obinutuzumab

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Severe and life-threatening thrombocytopenia has been reported during obinutuzumab therapy.(1) Anticoagulants and antiplatelets may have an additive risk of bleeding.

CLINICAL EFFECTS: Concurrent use of obinutuzumab with anticoagulants or antiplatelet agents may result in additive or synergistic effects, including fatal and non-fatal hemorrhage.(1)

PREDISPOSING FACTORS: The risk for bleeding episodes may be greater in patients with disease-associated factors (e.g. thrombocytopenia). Drug associated risk factors include concurrent use of multiple drugs which inhibit anticoagulant/antiplatelet metabolism and/or have an inherent risk for bleeding (e.g. NSAIDs).

PATIENT MANAGEMENT: Monitor all patients frequently for thrombocytopenia and signs of bleeding. Consider withholding concomitant anticoagulants and antiplatelets, especially during the first cycle of obinutuzumab.(1) If concurrent therapy is warranted, monitor patients receiving concurrent therapy for signs of blood loss, including decreased hemoglobin, hematocrit, fecal occult blood, and/or decreased blood pressure and promptly evaluate patients with any symptoms. When applicable, perform agent-specific laboratory test (e.g. INR, aPTT) to monitor efficacy and safety of anticoagulation. Discontinue anticoagulation in patients with active pathologic bleeding. Instruct patients to report any signs and symptoms of bleeding, such as unusual bleeding from the gums or nose; unusual bruising; red or black, tarry stools; red, pink or dark brown urine; acute abdominal or joint pain and/or swelling.

DISCUSSION: Obinutuzumab with chemotherapy has been reported to cause severe and life-threatening thrombocytopenia. Fatal hemorrhagic events have occurred in patients with NHL and CLL during obinutuzumab therapy, including during Cycle 1.(1)

Anticoagulants; Antiplatelets/Plasminogen

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Bleeding has been reported with the use of plasminogen.(1)

CLINICAL EFFECTS: Concurrent use of plasminogen with either anticoagulants or antiplatelets may increase the risk of active bleeding during plasminogen therapy, including bleeding from mucosal disease-related lesions that may manifest as gastrointestinal (GI) bleeding, hemoptysis, epistaxis, vaginal bleeding, or hematuria.(1)

PREDISPOSING FACTORS: The risk for bleeding episodes may be greater in patients with disease-associated factors (e.g. thrombocytopenia). Drug associated risk factors include concurrent use of multiple drugs which inhibit anticoagulant/antiplatelet metabolism and/or have an inherent risk for bleeding (e.g. NSAIDs).

PATIENT MANAGEMENT: Patients receiving concurrent therapy with plasminogen and anticoagulants and/or antiplatelets should be closely monitored during plasminogen therapy for active bleeding from mucosal disease-related lesions, including GI bleeding, hemoptysis, epistaxis, vaginal bleeding, or hematuria.(1) Prior to initiation of treatment with plasminogen, confirm healing of lesions or wounds suspected as a source of a recent bleeding event. Monitor patients during and for 4 hours after infusion when administering plasminogen with concurrent anticoagulants, antiplatelet drugs, or other agents which may interfere with normal coagulation.(1) If patient experiences uncontrolled bleeding (defined as any gastrointestinal bleeding or bleeding from any other site that persists longer than 30 minutes), seek emergency care and discontinue plasminogen immediately.(1) If concurrent therapy is warranted, monitor patients receiving concurrent therapy for signs of blood loss, including decreased hemoglobin, hematocrit, fecal occult blood, and/or decreased blood pressure and promptly evaluate patients with any symptoms. When applicable, perform agent-specific laboratory tests (e.g. INR, aPTT) to monitor efficacy and safety of anticoagulation. Discontinue anticoagulation in patients with active pathologic bleeding. Instruct patients to report any signs and symptoms of bleeding, such as unusual bleeding from the gums or nose; unusual bruising; red or black, tarry stools; red, pink or dark brown urine; acute abdominal or joint pain and/or swelling. The time of highest risk for a coumarin-type drug interaction is when the precipitant drug is initiated or discontinued. Contact the prescriber before initiating, altering the dose or discontinuing either drug.

DISCUSSION: Plasminogen has not been studied in patients at an increased risk of bleeding. Bleeding has been reported with plasminogen in a two single-arm, open-label clinical trials as well as in compassionate use programs. The incidence of hemorrhage in patients with Plasminogen Deficiency Type 1 was 16% (3/19 patients).(1) One of the bleeding events occurred two days after receiving the second dose of plasminogen in a patient with a recent history of GI bleeding due to gastric ulcers. The patient received plasminogen through a compassionate use program and the dose was 6.6 mg/kg body weight every 2 days. Endoscopy showed multiple ulcers with one actively bleeding ulcer near the pylorus.(1)

Anticoagulants; Antiplatelets/Tisotumab

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Bleeding, including hemorrhage, has been reported with the use of tisotumab.(1)

CLINICAL EFFECTS: Concurrent use of tisotumab with either anticoagulants, antiplatelets, or NSAIDs may increase the risk of hemorrhage.(1)

PREDISPOSING FACTORS: The risk for bleeding episodes may be greater in patients with disease-associated factors (e.g. thrombocytopenia). Drug associated risk factors include concurrent use of multiple drugs which inhibit anticoagulant/antiplatelet metabolism and/or have an inherent risk for bleeding (e.g. NSAIDs).

PATIENT MANAGEMENT: Patients receiving concurrent therapy with tisotumab and anticoagulants, antiplatelets, and/or NSAIDs should be closely monitored for signs and symptoms of bleeding and changes in platelet count or International Normalized Ratio (INR). For patients experiencing pulmonary or central nervous system (CNS) hemorrhage, permanently discontinue tisotumab. For grade 2 or greater hemorrhage in any other location, withhold until bleeding has resolved, blood hemoglobin is stable, there is no bleeding diathesis that could increase the risk of continuing therapy, and there is no anatomical or pathologic condition that can increase the risk of hemorrhage. After resolution, either resume treatment or permanently discontinue tisotumab.(1) If concurrent therapy is warranted, monitor patients receiving concurrent therapy for signs of blood loss, including decreased hemoglobin, hematocrit, fecal occult blood, and/or decreased blood pressure and promptly evaluate patients with any symptoms. When applicable, perform agent-specific laboratory tests (e.g. INR, aPTT) to monitor efficacy and safety of anticoagulation. Discontinue anticoagulation in patients with active pathologic bleeding. Instruct patients to report any signs and symptoms of bleeding, such as unusual bleeding from the gums or nose; unusual bruising; red or black, tarry stools; red, pink or dark brown urine; acute abdominal or joint pain and/or swelling. The time of highest risk for a coumarin-type drug interaction is when the precipitant drug is initiated or discontinued. Contact the prescriber before initiating, altering the dose or discontinuing either drug.

DISCUSSION: Hemorrhage occurred in 62% of patients with cervical cancer treated with tisotumab across clinical trials. The most common all grade hemorrhage adverse reactions were epistaxis (44%), hematuria (10%), and vaginal hemorrhage (10%). Grade 3 hemorrhage occurred in 5% of patients.(1)

H2 Antagonists/Atazanavir

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: H-2 antagonists increase gastric pH. As gastric pH increases, the solubility of atazanavir decreases.(1,2)

CLINICAL EFFECTS: Concurrent use of atazanavir and a H-2 antagonist may result in decreased levels and effectiveness of atazanavir.(1,2)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: The Australian and US manufacturers of atazanavir(1,2) and cobicistat(3,4) state that patients who require H-2 antagonist therapy should receive atazanavir 300 mg daily with ritonavir 100 mg daily or cobicistat 150 mg daily, taken with and/or at least 10 hours after the H-2 antagonist dose. Patients who are also on tenofovir in addition to atazanavir and a H-2 antagonist should receive atazanavir 400 mg daily with ritonavir 100 mg daily or cobicistat 150 mg daily.(2,3,5) The dose of the H-2 antagonist should not exceed the equivalent of famotidine 40 mg twice daily in treatment-naive patients, and 20 mg twice daily in treatment-experienced patients.(2-5) Treatment-experienced pregnant patients in the second or third trimester on concurrent tenofovir disoproxil should have their atazanavir dose increased to 400 mg with ritonavir 100 mg daily. The use of atazanavir with both a H2-antagonist and tenofovir in treatment-experienced pregnant women is not recommended.(2) The Australian manufacturer of atazanavir states that atazanavir without ritonavir is not recommended when co-administered with H-2 antagonists.(1) The US manufacturer of atazanavir states that treatment-naive patients who are unable to tolerate ritonavir or cobicistat should receive atazanavir 400 mg daily with food at least 2 hours before and at least 10 hours after the H-2 antagonist. The H-2 antagonist dose should not exceed the equivalent of a 20 mg single dose of famotidine and the total daily dose should not exceed a 40 mg equivalent dose of famotidine. Treatment-experienced patients should not use unboosted atazanavir with a H-2 antagonist.(2) The US manufacturer of atazanavir states that atazanavir should not be administered without ritonavir in pediatric patients at least 13 years of age who weigh at least 40 kg who are receiving a H2 antagonist. Data are not sufficient to recommend a dose of atazanavir in patients weighing less than 40 kg.(2)

DISCUSSION: In a study in 15 subjects, simultaneous administration of atazanavir (400 mg daily) with famotidine (40 mg twice daily) decreased the atazanavir maximum concentration (Cmax), area-under-curve (AUC), and minimum concentration (Cmin) by 47%, 41%, and 42%, respectively.(2) In a study in 14 subjects, atazanavir (400 mg daily) was administered 2 hours before and 10 hours after famotidine (40 mg twice daily). Atazanavir Cmax increased 8%. Atazanavir AUC and Cmin decreased by 5% and 21%, respectively.(2) In a study in 14 subjects, atazanavir (300 mg daily) and ritonavir (100 mg daily) were administered simultaneously with famotidine (40 mg twice daily). Atazanavir Cmax, AUC, and Cmin decreased by 14%, 18%, and 28%, respectively, compared to the same regimen alone. However, atazanavir Cmax was similar to levels seen with atazanavir 400 mg alone. Atazanavir AUC and Cmin were 1.79-fold and 4.46-fold higher than levels seen with atazanavir 400 mg alone.(2) In a study in 18 subjects, simultaneous administration of famotidine (20 mg twice daily) and atazanavir/ritonavir (300/100 mg daily) decreased the Cmax, AUC, and Cmin of atazanavir by 9%, 10%, and 19%, respectively.(2) In a study in 20 subjects, administration of atazanavir/ritonavir/tenofovir (300/100/300 mg daily) 12 hours after famotidine (40 mg daily) decreased the Cmax, AUC, and Cmin of atazanavir by 11%, 12%, and 23%, respectively.(2) In a study in 18 subjects, administration of atazanavir/ritonavir/tenofovir (300/100/300 mg daily) 12 hours after the evening dose and two hours before the morning dose of famotidine (40 mg twice daily) decreased the Cmax, AUC, and Cmin of atazanavir by 26%, 21%, and 28%, respectively.(2) In a study in 15 subjects, administration of atazanavir/ritonavir (400/100 mg) with famotidine (40 mg twice daily) decreased atazanavir Cmin by 14%. There were no significant effects on atazanavir Cmax or AUC.(2)

H2 Antagonists/Pritelivir

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: The aqueous solubility of pritelivir is pH dependent. Higher gastric pH leads to lower solubility which may reduce pritelivir absorption.(1)

CLINICAL EFFECTS: Coadministration of H2 receptor antagonists may reduce the bioavailability of pritelivir leading to decreased systemic levels and effectiveness.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Take pritelivir at least 2 hours before or 12 hours after H2 receptor antagonists.(1)

DISCUSSION: The combination of pritelivir with H2 receptor antagonists has not been studied. Pritelivir absorption is pH-dependent. Coadministration of a single oral dose of 100 mg pritelivir (on Day 1) with esomeprazole 40 mg once daily (from day -3 to Day 1; 4 days total) decreased maximum concentration (Cmax) by 76% and area-under-curve (AUC) by 59% compared to pritelivir administered alone.(1)

H2 Antagonists/Ravidasvir

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Absorption of ravidasvir may be reduced in patients receiving concomitant treatment with acid reducing agents.(1)

CLINICAL EFFECTS: Administration of H2 antagonists may reduce the bioavailability of ravidasvir, leading to decreased systemic levels and effectiveness.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: In order to assure systemic absorption and maximal effectiveness from use of this Hepatitis C treatment, counsel patients to administer H2 antagonists 4 hours after ravidasvir.(1)

DISCUSSION: Interaction studies with antacids have not been performed. Co-administration with H2 antagonists are expected to decrease ravidasvir plasma concentrations and potentially result in Hepatitis C treatment failure.(1)

H2 Antagonists/Rilzabrutinib

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Rilzabrutinib solubility decreases with increasing pH. H2 antagonist induced increase in gastric pH may result in a decrease in rilzabrutinib absorption.(1)

CLINICAL EFFECTS: Simultaneous administration of a H2 antagonist may result in decreased levels and effectiveness of rilzabrutinib.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Administer rilzabrutinib at least 2 hours before taking H2 antagonists.(1) Concurrent use of rilzabrutinib with proton pump inhibitors should be avoided.(1)

DISCUSSION: In an interaction study, administration of famotidine (H2 receptor antagonist) two hours after the evening dose of rilzabrutinib decreased the next morning dose of rilzabrutinib maximum concentration (Cmax) by 35% and area-under-curve (AUC) by 28%.(1)

H2 Antagonists/Selected Kinase Inhibitors

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: The solubility of dacomitinib,(1) erlotinib,(2) gefitinib,(3) and nilotinib(4) is pH dependent. Changes in gastric pH from H2 antagonists may decrease the absorption of dacomitinib,(1) erlotinib,(2) gefitinib,(3) and nilotinib(4).

CLINICAL EFFECTS: Use of H2 antagonists may result in decreased levels and effectiveness of dacomitinib,(1) erlotinib,(2) gefitinib,(3) and nilotinib(4).

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Consider the use of short-acting antacids in patients taking dacomitinib,(1) erlotinib,(2) gefitinib,(3) and nilotinib(4). If antacids are used, separate the administration times by several hours(1-7) but at least 2 hours for bosutinib,(1) and nilotinib,(4) and 6 hours for gefitinib.(3) If H2 antagonist therapy is required with dacomitinib, dacomitinib must be given once daily 10 hours after the H2 blocker and 6 hours before the next dose of the H2 blocker.(1) If H2 antagonist therapy is required with erlotinib or nilotinib, the kinase inhibitor must be given 10 hours after the H2 blocker and at least 2 hours before the next dose of the H2 blocker.(2-4) If H2 antagonist therapy is required with gefitinib, gefitinib should be given at least 6 hours before or after the H2 antagonist.(3) Avoid the use of proton pump inhibitors (PPIs) in patients receiving treatment dacomitinib,(1) erlotinib,(2) gefitinib,(3) and nilotinib(4).

DISCUSSION: In a study, concurrent rabeprazole decreased the Cmax and AUC of dacomitinib by 51% and 39%, respectively.(1) In a study, concurrent omeprazole decreased the AUC and Cmax of erlotinib by 46% and 61%, respectively.(2) In a study, administration of erlotinib two hours after a dose of ranitidine (300 mg), erlotinib AUC and Cmax decreased by 33% and 54%, respectively. Administration of erlotinib 10 hours after and two hours before ranitidine (150 mg twice daily), erlotinib AUC and Cmax decreased by 15% and 17%, respectively.(2) In a case report, a patient that was given erlotinib (150 mg daily,) with algeldrate/magnesium hydroxide (800/400 mg four times daily 4 hours before or 2 hours after erlotinib) did not see a significant reduction in serum trough concentrations of erlotinib. When the patient was switched to intravenous pantoprazole via continuous infusion (8 mg per hour), serum erlotinib levels decreased significantly below minimal trough concentrations for effective tyrosine kinase inhibition. When the patient was switched to oral pantoprazole (40 mg twice daily), serum trough levels of erlotinib returned to therapeutic levels.(5) In a study in 22 healthy subjects, pretreatment with esomeprazole (40 mg daily), decreased the Cmax and AUC of a single dose of nilotinib (400 mg) by 27% and 34%, respectively.(4,7) Increasing the dosage of nilotinib or separating the administration time of nilotinib and the proton pump inhibitor is not expected to eliminate the interaction.(4) There were no significant changes in nilotinib pharmacokinetics when famotidine was administered 10 hours before or 2 hours after nilotinib.(4) There were no significant changes in nilotinib pharmacokinetics when an antacid (aluminum hydroxide/magnesium hydroxide/simethicone) was administered 2 hours before or after nilotinib.(4)

H2 Antagonists; Proton Pump Inhibitors/Amphetamines

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: H2 antagonists and proton pump inhibitors (PPIs) may alter the timing of absorption of amphetamines.

CLINICAL EFFECTS: Concurrent use of amphetamines and H2 antagonists or PPIs may result in an increased absorption rate and a change in timing of peak amphetamine levels.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: The US manufacturer states that patients receiving concurrent amphetamines and H2 antagonists or PPIs should be monitored for changes in the timing and clinical effects of amphetamines.(1) Monitor patients receiving concurrent therapy for changes in amphetamine effectiveness and side effects. The Canadian manufacturer states that concurrent use of proton pump inhibitors and amphetamines should be avoided.(3)

DISCUSSION: During concurrent use of a proton pump inhibitor, the median time to maximum concentration (Tmax) of Adderall XR decreased from 5 hours to 2.75 hours.(3) In a 4-way crossover study in healthy subjects, omeprazole had no effect on the total exposure a single dose of mixed amphetamine salts (20 mg); however median Tmax decreased from 5 hours to 2.75 hours. Approximately 50% of subjects had a decrease in Tmax of equal to or greater than 1 hour.(4)

Ibuprofen; Indomethacin/Digoxin

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: The exact mechanism of this interaction is unknown, but it may involve decreased digoxin renal excretion.

CLINICAL EFFECTS: Increased levels of digoxin which may result in digoxin toxicity. Symptoms of digoxin toxicity can include anorexia, nausea, vomiting, headache, fatigue, malaise, drowsiness, generalized muscle weakness, hallucinations, visual disturbances, and arrhythmias.

PREDISPOSING FACTORS: Low body weight, advanced age, impaired renal function, hypokalemia, hypercalcemia, and/or hypomagnesemia may increase the risk of digoxin toxicity.

PATIENT MANAGEMENT: Digoxin levels should be monitored and patients should be monitored for signs of digoxin toxicity during concurrent therapy. The dosage of digoxin may need to be decreased by 15-30% or the frequency of administration may be reduced.

DISCUSSION: Although the documentation for this interaction is conflicting, caution is warranted. One study in 12 patients reported that serum digoxin levels were significantly increased (mean 59%) after concurrent administration of ibuprofen (1600 to 1800 mg/day) for seven days. However, there was no significant difference in digoxin levels after 28 days of concomitant therapy. In another study in eight patients, there was no significant change in digoxin serum concentration during concurrent administration of ibuprofen. Indomethacin-induced digoxin toxicity in three premature infants has been reported in one study. In another study, administration of indomethacin to 11 preterm infants who received intravenous digoxin followed by oral maintenance doses of digoxin resulted in a significant increase of digoxin serum concentration by 40.6% with a significant decrease in urine output by 47.7%. The digoxin half-life increased 125.5%. This study recommended decreasing the digoxin dosage by 50% when indomethacin is added to digoxin therapy in preterm infants until further assessments of urine output and digoxin levels are obtained. There are two case reports of digoxin toxicity in neonates following the addition of indomethacin to therapy. Administration of indomethacin to ten patients maintained on digoxin resulted in a 39.7% increase in digoxin concentrations. In contrast, the concurrent administration of indomethacin and digoxin in six healthy adults did not result in a significant pharmacokinetic or pharmacodynamic interaction. However, indomethacin did tend to elevate serum digoxin levels, strengthen the digoxin-induced decrease in ECG parameters and heart rate, and reduce the positive inotropic action of digoxin. In another study involving six healthy adults, the administration of indomethacin for three days followed by a single infusion of digoxin (750 mcg) did not affect any pharmacokinetic or pharmacodynamic parameters of digoxin.

Nsaids/Corticosteroids

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Concurrent use of NSAIDs and corticosteroids result in additive risk of GI ulceration.

CLINICAL EFFECTS: Concurrent use of NSAIDs and corticosteroids may increase the incidence and/or severity of GI irritation or ulceration, including increasing the risk for bleeding.

PREDISPOSING FACTORS: Risk of GI bleed may be increased in patients who are of older age, in poor health status, or who use alcohol or smoke. Risk may also be increased by concurrent use of anticoagulants, antiplatelets, selective serotonin reuptake inhibitors (SSRIs) or serotonin-norepinephrine reuptake inhibitors (SNRIs); with longer duration of NSAID use; and with prior history of peptic ulcer disease and/or GI bleeding. The risk for bleeding episodes may be greater in patients with disease-associated factors (e.g. thrombocytopenia, advanced liver disease).

PATIENT MANAGEMENT: Monitor patients receiving concurrent therapy carefully for signs of gastrointestinal ulceration. Use the lowest effective NSAID dose for the shortest duration possible. If concurrent therapy is warranted, monitor patients receiving concurrent therapy for signs of blood loss, including decreased hemoglobin, hematocrit, fecal occult blood, and/or decreased blood pressure and promptly evaluate patients with any symptoms. Instruct patients to report signs of GI bleeding such as black, tarry stools; "coffee ground" vomit; nausea; or stomach/abdominal pain.

DISCUSSION: Concurrent use of NSAIDs and corticosteroids increase the risk of GI bleeding.

Nsaids/Erlotinib

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: The exact mechanism is unknown.

CLINICAL EFFECTS: Concurrent use of NSAIDs may increase the risk of gastrointestinal bleeding and/or perforation in patients receiving erlotinib. Fatalities have been reported.(1)

PREDISPOSING FACTORS: Patients with a history of peptic ulceration or diverticular disease or who are receiving concomitant anti-angiogenic, corticosteroids, and/or taxane-based chemotherapy may be an increased risk of gastrointestinal perforation.(1) The risk for bleeding episodes may be greater in patients with disease-associated factors (e.g. thrombocytopenia). Drug associated risk factors include concurrent use of multiple drugs which inhibit anticoagulant/antiplatelet metabolism and/or have an inherent risk for bleeding.

PATIENT MANAGEMENT: Monitor patients receiving concurrent therapy for signs of gastrointestinal bleeding and/or perforation. Discontinue erlotinib in patients who develop gastrointestinal perforation.(1) If concurrent therapy is warranted, monitor patients receiving concurrent therapy for signs of blood loss, including decreased hemoglobin, hematocrit, fecal occult blood, and/or decreased blood pressure and promptly evaluate patients with any symptoms. Instruct patients to report any signs and symptoms of bleeding, such as unusual bleeding from the gums or nose; unusual bruising; red or black, tarry stools; red, pink or dark brown urine; acute abdominal or joint pain and/or swelling.

DISCUSSION: Infrequent cases of gastrointestinal bleeding were reported during erlotinib trials. Some cases were associated with NSAID administration.(1) In a phase II trial of concurrent bevacizumab plus erlotinib, 2 of 13 patients suffered fatal gastrointestinal perforations.(2) In another phase II trial of concurrent bevacizumab with erlotinib, 1 of 104 patients died of gastrointestinal perforation.(3)

Nsaids/Heparins

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Heparin inhibits thrombosis by inactivating activated Factor X and inhibiting the conversion of prothrombin to thrombin.(1) NSAIDs inhibit coagulation by interfering with platelet-aggregation, while inhibition of prostaglandin synthesis increases the risk for gastrointestinal bleeding.

CLINICAL EFFECTS: Concurrent use of heparin and an NSAID may increase the risk for bleeding.(1,2)

PREDISPOSING FACTORS: The risk for bleeding episodes may be greater in patients with multiple disease-associated factors (e.g. thrombocytopenia, advanced liver disease). Drug associated risk factors include concurrent use of multiple drugs which inhibit anticoagulant/antiplatelet metabolism and/or have an inherent risk for bleeding (e.g., other anticoagulants, antiplatelets, corticosteroids, selective serotonin reuptake inhibitors (SSRIs) or serotonin-norepinephrine reuptake inhibitors (SNRIs). Risk of GI bleed may be increased in patients who are of older age, in poor health status, or who use alcohol or smoke. Risk may also be increased with longer duration of NSAID use and prior history of peptic ulcer disease and/or GI bleeding.

PATIENT MANAGEMENT: Manufacturers recommend caution and monitoring when using this combination of drugs.(1,2) If concurrent therapy is warranted, monitor patients receiving concurrent therapy for signs of blood loss, including decreased hemoglobin, hematocrit, fecal occult blood, and/or decreased blood pressure and promptly evaluate patients with any symptoms. When applicable, perform agent-specific laboratory test (e.g. INR, aPTT) to monitor efficacy and safety of anticoagulation. Discontinue anticoagulation in patients with active pathologic bleeding. Instruct patients to report any signs and symptoms of bleeding, such as unusual bleeding from the gums or nose; unusual bruising; red or black, tarry stools; red, pink or dark brown urine; acute abdominal or joint pain and/or swelling.

DISCUSSION: Based upon drug mechanisms of action, careful monitoring would be prudent.

Nsaids; Aspirin (Non-Cardioprotective)/Beta-Blockers

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Unknown; however, possibly related to inhibition of prostaglandin by NSAIDs.

CLINICAL EFFECTS: The antihypertensive action of beta-blockers may be decreased.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Monitor patient's blood pressure and adjust the dose of the beta-blocker as needed.

DISCUSSION: Concurrent administration of beta-blockers and NSAIDs has been associated with a clinically significant loss in antihypertensive response. The magnitude of the effect of NSAIDs on control of blood pressure by beta-blockers needs to be determined for each anti-inflammatory agent. One or more of the drug pairs linked to this monograph have been included in a list of interactions that could be considered for classification as "non-interruptive" in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology.

Nsaids; Aspirin (Non-Cardioprotective)/Metoprolol

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Unknown; however, possibly related to inhibition of prostaglandin by NSAIDs.

CLINICAL EFFECTS: The antihypertensive action of metoprolol may be decreased.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Monitor patient's blood pressure and adjust the dose of metoprolol as needed.

DISCUSSION: Concurrent administration of metoprolol and NSAIDs has been associated with a clinically significant loss in antihypertensive response. The magnitude of the effect of NSAIDs on control of blood pressure by beta-blockers needs to be determined for each anti-inflammatory agent. One or more of the drug pairs linked to this monograph have been included in a list of interactions that could be considered for classification as "non-interruptive" in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology.

Nsaids; Salicylates/Aldosterone Receptor Antag; Baxdrostat

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: The exact mechanism is unknown; however, nonsteroidal anti-inflammatory (NSAID) inhibition of prostaglandins may allow baxdrostat, eplerenone, finerenone, or spironolactone-induced nephrotoxicity or hyperkalemia to occur in some patients.(1-4) In some patients, NSAIDs may reduce the diuretic, natriuretic and antihypertensive effects of baxdrostat, eplerenone, finerenone, or spironolactone.(1-4)

CLINICAL EFFECTS: Concurrent use of baxdrostat, eplerenone, finerenone, or spironolactone with NSAIDs may result in renal failure or hyperkalemia. The effects of the diuretic, natriuretic, or antihypertensive effects of baxdrostat, eplerenone, finerenone, or spironolactone may be decreased.(1-4)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: When possible, avoid concurrent therapy with baxdrostat, eplerenone, finerenone, or spironolactone with NSAIDs. If these agents are used concurrently, monitor renal function and serum electrolytes. If decreased renal function or hyperkalemia develops, discontinue both agents. The manufacturer of eplerenone recommends checking serum potassium and serum creatinine within 3-7 days of concurrent therapy with NSAIDs.(1) The manufacturer of spironolactone states concurrent use with NSAIDs may lead to severe hyperkalemia and extreme caution should be used during concurrent therapy.(2)

DISCUSSION: Although acute renal failure and hyperkalemia have only been reported in studies and case reports involving indomethacin, diclofenac, flurbiprofen, and ibuprofen with either triamterene or amiloride, the proposed mechanism suggests that all nonsteroidal anti-inflammatory agents may be capable of this interaction with all potassium-sparing diuretics. Patients receiving diuretics are at an increased risk of NSAID-induced renal failure.

Nsaids; Salicylates/Aliskiren

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: The exact mechanism is unknown. It is believed to be related to inhibition of prostaglandin synthesis by the NSAIDs. Use of an NSAID in combination with aliskiren, whose hypotensive effects may be related to the increase in hypotensive prostaglandins, may negate any decrease in blood pressure.

CLINICAL EFFECTS: Concurrent use of aliskiren with NSAIDs may result in decreased antihypertensive effects. In patients with existing renal impairment, the use of these agents together may also result in further deterioration of renal clearance caused by renal hypoperfusion.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Patients maintained on aliskiren should be monitored for a loss of blood pressure control and a change in renal function if an NSAID is added to their regimen. Patients receiving concurrent therapy may require higher doses of aliskiren. If blood pressure control cannot be achieved or if the patient's renal function deteriorates, the NSAID may need to be discontinued. Patients should be monitored for hypotension if NSAIDs are withdrawn from concurrent aliskiren therapy.

DISCUSSION: Indomethacin has been shown to inhibit the antihypertensive effect of captopril, cilazapril, enalapril, losartan, perindopril, and valsartan. Ibuprofen has been shown to decrease the antihypertensive effects of captopril. Two separate case reports describe individuals suspected of ACEI-associated angioedema precipitated by NSAIDs. Both cases reported symptom resolution after cessation of the NSAID. Studies have shown that sulindac does not affect the antihypertensive effects of captopril and enalapril.

Nsaids; Salicylates/Angiotensin Ii Receptor Blocker (Arb)

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Angiotensin II receptor blockers (ARBs) can cause vasodilation of the efferent renal arteriole which may result in decreased glomerular filtration rate. NSAIDs inhibit prostaglandin synthesis which can lead to afferent arteriolar vasoconstriction and may negate any decrease in blood pressure.

CLINICAL EFFECTS: Concurrent use of ARBs with NSAIDs may result in decreased antihypertensive effects. In patients with existing renal impairment, the use of these agents together may also result in further deterioration of renal clearance caused by renal hypoperfusion. Concurrent use of ARBs with NSAIDs and diuretics may result in increased risk of acute kidney injury (AKI).

PREDISPOSING FACTORS: Low water intake/dehydration, drug sensitivity, greater than 75 years of age, and use of diuretics can lead to hypovolemia and increased risk of AKI.

PATIENT MANAGEMENT: Patients maintained on ARBs should be monitored for a loss of blood pressure control and a change in renal function if an NSAID is added to their regimen. Patients receiving concurrent therapy may require higher doses of ARBs. If blood pressure control cannot be achieved or if the patient's renal function deteriorates, the NSAID may need to be discontinued. Patients should be monitored for hypotension if NSAIDs are withdrawn from concurrent ARB therapy. Concurrent use of ARBs with NSAIDs and diuretics should be used with caution and monitored for signs of AKI.

DISCUSSION: In a computational study, the risk of AKI using triple therapy (combination of a diuretic, renin-angiotensin system (RAS) inhibitor, and NSAID) was assessed. The study found the following factors may increase an individual's susceptibility to AKI: low water intake, drug sensitivity, greater than 75 years of age, and renal impairment.(22,23) In an observational study, current use of a triple therapy combination was associated with an increased rate of acute kidney injury (rate ratio (RR) 1.31, 95% confidence interval (CI) 1.12-1.53). The highest risk of AKI associated with triple therapy were observed in the first 30 days of use (RR 1.82, CI 1.35-2.46).(24) In a population based cohort study, the concurrent use of NSAIDs with renin-angiotensin system (RAS) inhibitors in 5,710 hypertensive patients stabilized on antihypertensive therapy required hypertension treatment intensification. Adjusted hazard ratios (HR) for hypertension treatment intensification were 1.34 [95% CI 1.05-1.71] for NSAIDs in general, 1.79 (95% CI 1.15-2.78) for diclofenac and 2.02 (95% CI 1.09-3.77) for piroxicam. There were significant interactions between NSAIDs and angiotensin converting enzyme inhibitors (ACE inhibitors; HR 4.09, 95% CI 2.02-8.27) or angiotensin receptor blockers (ARBs; HR 3.62, 95% CI 1.80-7.31), but not with other antihypertensive drugs.

Nsaids; Salicylates/Drospirenone

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Drospirenone has antimineralocorticoid activity and may cause hyperkalemia. NSAIDs may also increase potassium levels.(1)

CLINICAL EFFECTS: Concurrent use of drospirenone and NSAIDs may result in hyperkalemia.(1)

PREDISPOSING FACTORS: Renal insufficiency, hepatic dysfunction, adrenal insufficiency, and use of potassium supplements, ACE inhibitors, angiotensin II receptor antagonists, heparin, and potassium-sparing diuretics may increase potassium levels.(1)

PATIENT MANAGEMENT: Patients receiving drospirenone with a NSAID should have their serum potassium level checked during the first treatment cycle.(1)

DISCUSSION: Drospirenone has antimineralocorticoid activity comparable to 25 mg of spironolactone and may result in hyperkalemia. Concurrent use of NSAIDs may also increase potassium levels.(1) Occasional or chronic use of NSAIDs was not restricted in clinical trials of drospirenone.(1)

Nsaids; Salicylates/Lithium

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Decreased renal excretion of lithium, possibly resulting from NSAID-induced prostaglandin inhibition.

CLINICAL EFFECTS: May observe increased lithium toxicity.

PREDISPOSING FACTORS: Risk factors for lithium toxicity include: renal impairment or worsening of existing renal disease, dehydration, low sodium diet, and concomitant use of multiple medications which may impair renal elimination of lithium (e.g. ARBs, ACE Inhibitors, NSAIDs, diuretics). Patients who require higher therapeutic lithium levels to maintain symptom control are particularly susceptible to these factors.

PATIENT MANAGEMENT: The magnitude of this interaction is highly variable. Patients with predisposing factors, e.g. dehydration, renal impairment, or concurrent use of other agents which may impair lithium elimination, are expected to have a higher risk for lithium toxicity. If both drugs are administered, monitor plasma lithium levels and observe the patient for signs and symptoms of lithium toxicity or changes in renal function. Full effects of the addition or an increase in NSAID dose may not be seen for one to two weeks. Adjust the dose of lithium accordingly. If lithium is to be started in a patient stabilized on chronic NSAID therapy, consider starting with a lower lithium dose and titrate slowly as half-life may be prolonged. Monitor lithium concentrations until stabilized on the combination. Counsel the patient to contact their prescriber before starting an OTC NSAID. Assure that patients are familiar with signs and symptoms of lithium toxicity (e.g. new or worsening tremor, nausea/vomiting, diarrhea, ataxia, or altered mental status) and to report signs and symptoms of toxicity.

DISCUSSION: Numerous studies and case reports have been documented that administration of a NSAID to a patient stabilized on lithium therapy may result in increased serum lithium levels and possible toxicity. Full effects may take 1 to 2 weeks to develop and may persist for a week after the NSAID is discontinued.

Nsaids; Salicylates/Loop Diuretics

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: During concurrent administration of a loop diuretic and a nonsteroidal anti-inflammatory drug (NSAID), patients may retain sodium as a result of NSAID-induced prostaglandin inhibition.

CLINICAL EFFECTS: The pharmacological effects of loop diuretics may be decreased due to reduced antihypertensive and diuretic actions. Concurrent use of NSAIDs with loop diuretics and renin-angiotensin system (RAS) inhibitors may result in increased risk of acute kidney injury (AKI).

PREDISPOSING FACTORS: Low water intake/dehydration, drug sensitivity, greater than 75 years of age, and renal impairment may increase an individuals susceptibility to AKI.

PATIENT MANAGEMENT: Monitor patients for a decrease in the effects of the loop diuretic. It may be necessary to administer a higher dose of the diuretic or an alternative anti-inflammatory agent. Concurrent use of NSAIDs with loop diuretics and RAS inhibitors should be used with caution and monitored closely for signs of AKI.

DISCUSSION: In a computational study, the risk of AKI using triple therapy with a diuretic, RAS inhibitor, and NSAID was assessed. The study found the following factors may increase an individual's susceptibility to AKI: low water intake, drug sensitivity, greater than 75 years of age, and renal impairment.(19,20) In an observational study, current use of a triple therapy with a diuretic, RAS inhibitor, and NSAID, was associated with an increased rate of acute kidney injury (rate ratio (RR) 1.31, 95% confidence interval (CI) 1.12-1.53). The highest risk of AKI associated with triple therapy were observed in the first 30 days of use (RR 1.82, CI 1.35-2.46). (21) Administration of indomethacin alone has been reported to decrease sodium excretion and increase blood pressure. In patients receiving a loop diuretic (e.g., bumetanide, furosemide), these effects interfere with clinical management. Several NSAIDs have been shown to interact with loop diuretics interfering with the pharmacological effects of the diuretic. In volunteers on sodium restricted diets, ibuprofen and indomethacin inhibited furosemide diuresis.

Nsaids; Salicylates/Minoxidil

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Oral minoxidil functions as a direct-acting peripheral vasodilator, lowering elevated systolic and diastolic blood pressure by reducing resistance in peripheral blood vessels. This triggers a compensatory increase in cardiac output and renin secretion and results in sodium and water retention. NSAIDs inhibit prostaglandin synthesis and also result in sodium and water retention.(1,2)

CLINICAL EFFECTS: The risk of heart failure may increase with oral minoxidil and NSAIDs due to their combined effects on blood vessel dilation, fluid retention, and altered sodium balance. Minoxidil efficacy may be compromised.(1,2)

PREDISPOSING FACTORS: Higher doses of oral minoxidil have been associated with serious adverse events, including hypotensive syncope, pericarditis, pericardial effusion, and myocardial infarction.(1-5)

PATIENT MANAGEMENT: Closely monitor body weight, fluid and electrolyte balance, and blood pressure when using oral minoxidil and NSAIDs concurrently. Minoxidil tablets should be co-administered with an appropriate diuretic to prevent fluid retention and potential congestive heart failure. A high-ceiling (loop) diuretic is often necessary alongside vigilant monitoring of body weight. Without concurrent diuretic use, minoxidil may lead to the retention of salt and water within a few days.(1,2)

DISCUSSION: While the manufacturer of minoxidil does not provide specific recommendations regarding NSAID co-administration, it emphasizes the necessity of combining minoxidil with a beta-blocker to prevent tachycardia and increased myocardial workload. Additionally, concurrent use with a diuretic is recommended to avert serious fluid accumulation and potential congestive heart failure. NSAID labeling warns about fluid retention, edema, an elevated risk of heart failure, and potential drug interactions with beta-blockers and diuretics which can result in a blunting of the antihypertensive and cardiovascular effects of these agents.(1-5)

Nsaids; Salicylates/Sparsentan

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Sparsentan is an endothelin and angiotensin II receptor antagonist.(1) Angiotensin II receptor blockers can cause vasodilation of the efferent renal arteriole which may result in decreased glomerular filtration rate. NSAIDs inhibit prostaglandin synthesis which can lead to afferent arteriolar vasoconstriction.

CLINICAL EFFECTS: Concurrent use of sparsentan with NSAIDs (including selective COX-2 inhibitors) may result in renal hypoperfusion and deterioration of renal clearance, including possible acute kidney injury (AKI). These effects are usually reversible.(1)

PREDISPOSING FACTORS: Patients older than 75 years old, with renal artery stenosis, chronic kidney disease, severe congestive heart failure, or volume depletion (including from diuretic use and dehydration) may be at greater risk for AKI.(1-3)

PATIENT MANAGEMENT: Monitor for signs of worsening renal function if an NSAID (including selective COX-2 inhibitors) is used concurrently with sparsentan. If renal function deteriorates, the NSAID may need to be discontinued.(1)

DISCUSSION: In a computational study, the risk of AKI using triple therapy with a diuretic, renin-angiotensin system (RAS) inhibitor, and NSAID was assessed. The study found the following factors may increase an individual's susceptibility to AKI: low water intake, drug sensitivity, greater than 75 years of age, and renal impairment.(2,3) In an observational study, current use of a triple therapy combination was associated with an increased rate of acute kidney injury (rate ratio (RR) 1.31, 95% confidence interval (CI) 1.12-1.53). The highest risk of AKI associated with triple therapy were observed in the first 30 days of use (RR 1.82, CI 1.35-2.46).(4)

Nsaids; Salicylates/T Cell Immunotherapies

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: NSAIDs augment the immune system. Concurrent use with NSAIDs may interfere with the activity of CAR-T cell immunotherapies.(1)

CLINICAL EFFECTS: NSAIDs may decrease the efficacy of CAR-T cell immunotherapies.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: NSAIDs should be used with caution with or after CAR-T cell immunotherapy.(1)

DISCUSSION: An in vitro study showed aspirin and celecoxib negatively affected CD19.CAR-T cells through their effects on the induction of apoptosis, reduction of activation, and impairment of proliferation.(1)

Sel Oral Cations; Antacids; H2 Antag/Dolutegravir-Rilpivirin

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Aluminum, calcium, iron, lanthanum, magnesium, sucralfate, and zinc may form chelation compounds with dolutegravir.(1) Rilpivirine requires an acidic medium for absorption. Antacid or H2 antagonist induced decrease in gastric pH may result in decrease in rilpivirine absorption.(1)

CLINICAL EFFECTS: Simultaneous administration or administration of products containing aluminum, calcium, iron, lanthanum, magnesium, and/or sucralfate close to the administration time of dolutegravir may result in decreased absorption and clinical effectiveness of dolutegravir.(1) Simultaneous administration of an antacid or a H2 antagonist may result in decreased levels and effectiveness of rilpivirine, as well as the development of resistance.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: If possible, avoid concurrent therapy with dolutegravir-rilpivirine and cation-containing products. If it is necessary to use these agents concurrently, dolutegravir-rilpivirine should be administered 4 hours before or 6 hours after taking these medications.(1) Alternatively, dolutegravir-rilpivirine and supplements containing calcium or iron can be taken together with food.(1) In patients maintained on dolutegravir-rilpivirine, administer dolutegravir-rilpivirine at least 4 hours before or 6 hours after antacids .(1) In patients maintained on dolutegravir-rilpivirine, administer dolutegravir-rilpivirine at least 4 hours before or 12 hours after H2 antagonists.(1) Concurrent use of proton pump inhibitors will dolutegravir-rilpivirine is contraindicated.(1)

DISCUSSION: In a study in 16 subjects, the administration of an antacid (Maalox - aluminum and magnesium hydroxide) simultaneously with dolutegravir (50 mg single dose) decreased the maximum concentration (Cmax), area-under-curve (AUC), and minimum concentration (Cmin) of dolutegravir by 72%, 74%, and 74%, respectively.(1) In a study in 16 subjects, the administration of an antacid (Maalox - aluminum and magnesium hydroxide) 2 hours after dolutegravir (50 mg single dose) decreased dolutegravir Cmax, AUC, and Cmin by 18%, 26%, and 30%, respectively.(1) In a study in 16 subjects, the administration of a multiple vitamin (One-A-Day) simultaneously with dolutegravir (50 mg single dose) decreased dolutegravir Cmax, AUC, and Cmin by 35%, 33%, and 32%, respectively.(1) In a study in 16 subjects, omeprazole (20 mg daily) decreased the Cmax, AUC, and Cmin of rilpivirine (150 mg daily) by 40%, 40%, and 33%, respectively. The Cmax and AUC of omeprazole decreased by 14% and 14%, respectively.(1) In a study in 24 subjects, famotidine (40 mg single dose) administered 12 hours before a single dose of rilpivirine (150 mg) had no significant effect on rilpivirine Cmax or AUC.(1) In a study in 23 subjects, famotidine (40 mg single dose) administered 2 hours before a single dose of rilpivirine (150 mg) decreased the rilpivirine Cmax and AUC by 85% and 76%, respectively.(1) In a study in 24 subjects, famotidine (40 mg single dose) administered 4 hours before a single dose of rilpivirine (150 mg) increased the rilpivirine Cmax and AUC by 21% and 13%, respectively.(1)

Selected Anticoagulants; Antiplatelets/Ibrutinib

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Ibrutinib administration lowers platelet count in the majority of patients.(1,2) In addition, ibrutinib has been shown to inhibit collagen-mediated platelet aggregation.(3-4) Bleeding has been reported with the use of ibrutinib,(1-4) anticoagulants, or antiplatelets alone.

CLINICAL EFFECTS: Concurrent use of ibrutinib with either anticoagulants or antiplatelets may increase the risk of hemorrhage.

PREDISPOSING FACTORS: The risk for bleeding episodes may be greater in patients with disease-associated factors (e.g. thrombocytopenia). Drug associated risk factors include concurrent use of multiple drugs which inhibit anticoagulant/antiplatelet metabolism and/or have an inherent risk for bleeding (e.g. NSAIDs).

PATIENT MANAGEMENT: The Canadian product monograph for ibrutinib recommends concurrent use with anticoagulants or antiplatelets should be approached with caution. If therapeutic anticoagulation is required, consider temporarily withholding ibrutinib therapy until stable anticoagulation in achieved.(2) The US prescribing information for ibrutinib states patients receiving concurrent therapy with ibrutinib and anticoagulants and/or antiplatelets should be closely monitored for changes in platelet count or in International Normalized Ratio (INR). Carefully weigh the risks vs. benefits of concurrent therapy in patients with significant thrombocytopenia. If a bleeding event occurs, follow manufacturer instructions for ibrutinib dose adjustment.(1) If concurrent therapy is warranted, monitor patients receiving concurrent therapy for signs of blood loss, including decreased hemoglobin, hematocrit, fecal occult blood, and/or decreased blood pressure and promptly evaluate patients with any symptoms. When applicable, perform agent-specific laboratory tests (e.g. INR, aPTT) to monitor efficacy and safety of anticoagulation. Discontinue anticoagulation in patients with active pathologic bleeding. Instruct patients to report any signs and symptoms of bleeding, such as unusual bleeding from the gums or nose; unusual bruising; red or black, tarry stools; red, pink or dark brown urine; acute abdominal or joint pain and/or swelling. The time of highest risk for a coumarin-type drug interaction is when the precipitant drug is initiated or discontinued. Contact the prescriber before initiating, altering the dose or discontinuing either drug.

DISCUSSION: Bleeding has been reported with ibrutinib alone.(1-3) Across 27 clinical trials, grade 3 or higher bleeding events, e.g. subdural hematoma, gastrointestinal bleeding or hematuria, have occurred in up to 4% of patients, with 0.4% fatality. Grade 3 or 4 thrombocytopenia occurred in 5-19% of patients. Bleeding events of any grade occurred in 39% of patients treated with ibrutinib.(1) Concurrent use of anticoagulants or antiplatelets has been reported to increase the risk for major bleeding. In clinical trials, major bleeding occurred in 3.1% of patients taking ibrutinib without concurrent anticoagulants or antiplatelets, 4.4% of patients on concurrent antiplatelets with or without anticoagulants, and 6.1% of patients on concurrent anticoagulants with or without antiplatelets.(1) In an open-label, phase 2 trial of patients with relapsed/refractory mantle cell lymphoma on ibrutinib, 61 patients (55%) on concurrent anticoagulants or antiplatelets had a higher rate of bleeding (69% any grade, 8% grade 3-4) than patients not on anticoagulants or antiplatelets (28% any grade, 4% grade 3-4).(5) A retrospective trial found a hazard ratio of 20 (95% CI, 2.1-200) for patients on ibrutinib with concurrent anticoagulants and antiplatelets. There was a trend towards an increased bleeding risk in patients on either anticoagulants or antiplatelets, but this was not statistically significant on multivariate analysis.(6) A case report of 2 patients with chronic lymphocytic leukemia (CLL) on ibrutinib and dabigatran demonstrated no stroke nor bleeding events during the mean 11.5 month follow-up.(7) A case report of 4 patients with lymphoproliferative disease on concurrent dabigatran and ibrutinib demonstrated no stroke nor major bleeding events. 1 patient experienced grade 2 conjunctival hemorrhage whilst on both ibrutinib and dabigatran. The anticoagulant was withheld and successfully re-initiated at a lower dose with no further bleeding events.(8)

Selected H2 Antagonists/Bosutinib; Neratinib

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: The solubility of bosutinib(1) and neratinib(2) is pH dependent. Changes in gastric pH from H2 antagonists may decrease the absorption of bosutinib and neratinib.

CLINICAL EFFECTS: Use of H2 antagonists may result in decreased levels and effectiveness of bosutinib(1) and neratinib.(2)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Consider the use of short-acting antacids in patients taking bosutinib(1) and neratinib.(2) If antacids are used, separate the administration times by at least 2 hours for bosutinib(1) and 3 hours for neratinib.(2) If H2 antagonist therapy is required with bosutinib, separate administration of the H2 blocker by at least 2 hours before or 2 hours after bosutinib.(1) If H2 antagonist therapy is required with neratinib, then neratinib must be given 10 hours after the H2 blocker and at least 2 hours before the next dose of the H2 blocker.(2) Avoid the use of proton pump inhibitors (PPIs) in patients receiving treatment with bosutinib(1) and neratinib.(2)

DISCUSSION: A single dose of bosutinib 400 mg was administered alone or following multiple doses of lansoprazole 60 mg without food. Lansoprazole decreased bosutinib maximum concentration (Cmax) and area-under-curve (AUC) by 46% and 26%, respectively.(1) In a study in 15 healthy subjects, lansoprazole 30 mg daily decreased the Cmax and AUC of a single dose of neratinib (240 mg) by 71% and 65%, respectively.(2)

Selected H2 Antagonists/Pexidartinib

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: The solubility of pexidartinib is pH dependent. Changes in gastric pH from H2 antagonists may decrease the absorption of pexidartinib.(1)

CLINICAL EFFECTS: Use of H2 antagonists may result in decreased levels and effectiveness of pexidartinib.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Consider the use of short-acting antacids in patients taking pexidartinib. If antacids are used, separate the administration times by at least 2 hours. If H2 antagonist therapy is required, the pexidartinib must be given 10 hours after the H2 blocker and at least 2 hours before the next dose of the H2 blocker. Avoid the use of proton pump inhibitors (PPIs).(1)

DISCUSSION: Coadministration of esomeprazole decreased pexidartinib maximum concentration (Cmax) and area-under-curve (AUC) by 55% and 50%, respectively.(1)

Selected Nephrotoxic Agents/Adefovir

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Recommended doses of adefovir have been associated with delayed nephrotoxicity.(1-4) Concurrent administration of other nephrotoxic agents may result in additive or synergistic effects on renal function.(1)

CLINICAL EFFECTS: Concurrent use of adefovir with nephrotoxic agents such as intravenous aminoglycosides, amphotericin B, cyclosporine, tacrolimus,tenofovir, vancomycin, voclosporin and non-steroidal anti-inflammatory agents may result in renal toxicity.(1) Other nephrotoxic agents include capreomycin, cisplatin, gallium nitrate, high-dose methotrexate, intravenous pentamidine, and streptozocin.

PREDISPOSING FACTORS: Patients with pre-existing renal impairment(1,2) or receiving multiple nephrotoxic agents appear to be at greater risk for nephrotoxicity.

PATIENT MANAGEMENT: Evaluate renal function prior to initiation of concurrent therapy and continue renal function monitoring during therapy. Dose adjustments may be required for impaired renal function. Weigh the risks and benefits of concurrent therapy in patients with treatment-emergent nephrotoxicity.

DISCUSSION: Because of the known risks for adefovir nephrotoxicity, particularly at higher than recommended doses, the safety of adefovir has not been studied in patients receiving other known potentially nephrotoxic agents.

Selected Nephrotoxic Agents/Cisplatin

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: The nephrotoxic effects of aminoglycosides or non-steroidal anti-inflammatory drugs (NSAIDs) may be additive to those of cisplatin.

CLINICAL EFFECTS: The concurrent administration of amikacin, gentamicin, tobramycin, or NSAIDs with cisplatin may result in additive nephrotoxic effects.(1,2,5,6)

PREDISPOSING FACTORS: Pre-existing renal insufficiency, advanced age, dehydration may increase the risk of nephrotoxicity.(1,5,6)

PATIENT MANAGEMENT: The US labeling for aminoglycosides and cisplatin states that the concurrent use of aminoglycosides and cisplatin should be avoided.(1,3,4,6) Inform patients that concurrent cisplatin and aminoglycosides or NSAIDs can cause nephrotoxicity and that renal function and electrolyte monitoring during treatment is necessary.(2)

DISCUSSION: The US manufacturers of amikacin, gentamicin and tobramycin state that since the nephrotoxic effects of these medications may be additive, avoid concurrent or sequential use of other neurotoxic and/or nephrotoxic agents including cisplatin.(1,3,6)

Selected Nephrotoxic Agents/Immune Globulin Iv (Igiv)

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Immune Globulin Intravenous (IGIV) products, particularly those containing sucrose, can cause renal dysfunction, acute renal failure, osmotic nephrosis, and/or death. Concurrent administration of other nephrotoxic agents may result in additive or synergistic effects on renal function.(1-4)

CLINICAL EFFECTS: Concurrent use of Immune Globulin Intravenous (IGIV) products with nephrotoxic agents such as adefovir, intravenous aminoglycosides, amphotericin B, non-steroidal anti-inflammatory agents, tenofovir, and vancomycin may result in renal toxicity.(1-4) Other nephrotoxic agents include capreomycin, gallium nitrate, and streptozocin.

PREDISPOSING FACTORS: Patients at risk of acute renal failure include those with any degree of pre-existing renal insufficiency, diabetes mellitus, advanced age (above 65 years of age), volume depletion, sepsis, paraproteinemia, or receiving known nephrotoxic drugs.(1-4) Renal dysfunction and acute renal failure occur more commonly in patients receiving IGIV products containing sucrose.(3-4)

PATIENT MANAGEMENT: For patients at risk of renal dysfunction or renal failure, the US manufacturers of Immune Globulin Intravenous (IGIV) products recommends administration at the minimum dose and infusion rate practicable; ensure adequate hydration in patients before administration; and monitor renal function and urine output with assessment of blood urea nitrogen (BUN) and serum creatinine before initial infusion and at regular intervals during therapy.(1-3) Concurrent administration of potentially nephrotoxic agents should be avoided.(1) Review prescribing information for IGIV product to be administered for sucrose content. If concurrent therapy is warranted, monitor renal function closely. In high risk patients, consider selecting an IGIV product that does not contain sucrose.

DISCUSSION: The safety of Immune Globulin Intravenous (IGIV) has not been studied in patients receiving other known potentially nephrotoxic agents. Renal impairment is a major toxicity of IGIV products.(1-3) A review of the FDA renal adverse events (RAEs) (i.e. acute renal failure or insufficiency) from June 1985 to November 1998 identified 120 reports worldwide associated with IGIV administration. In the US, the FDA received 88 reports of cases with clinical and/or laboratory findings consistent with RAE (i.e. increased serum creatinine, oliguria, and acute renal failure). Patient cases involved a median age of 60.5 years and 55% were male. Of the 54 patients who developed acute renal failure, 65% were greater than 65 years, 56% had diabetes, and 26% had prior renal insufficiency; 59% had one, 35% had two, and 6% had three of these conditions. Upon review of the IGIV product received, 90% of cases received sucrose-containing IGIV products with the remaining patients receiving either maltose- or glucose-containing products. Approximately 40% of affected patients required dialysis and RAE may have contributed to death in 15% of patients.(4)

Selected Nephrotoxic Agents/Tenofovir

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Tenofovir and other nephrotoxic agents may result in additive or synergistic effects on renal function and increase nephrotoxicity risk.(1)

CLINICAL EFFECTS: Concurrent use of tenofovir and other nephrotoxic agents may result in renal toxicity and acute renal failure.(1) Reports of acute renal failure and Fanconi syndrome have been reported with tenofovir use.(2,3) However, this has been reported in 3 case reports and the renal failure may have been complicated by other pre-existing conditions.(2)

PREDISPOSING FACTORS: Pre-existing renal dysfunction, long duration of use, low body weight, concomitant use of drugs that may increase tenofovir levels may increase the risk of nephrotoxicity.(1)

PATIENT MANAGEMENT: The US prescribing information for tenofovir recommends avoiding concurrent or recent use of a nephrotoxic agent.(3) Evaluate renal function prior to initiation of concurrent therapy and continue renal function monitoring during therapy. Dose adjustments may be required for impaired renal function. Tenofovir should be avoided with high-dose or multiple NSAIDs. Alternatives to NSAIDs should be considered in patients at risk for renal dysfunction.(3) Patients receiving concurrent NSAIDs with tenofovir should be monitored for possible renal toxicity.(1,2) The dosing interval should be adjusted in patients with a baseline creatinine clearance of less than 50 ml/min.(1-3)

DISCUSSION: From March 18, 2003 to December 1, 2005, Health Canada received 10 reports of nephrotoxic reactions with tenofovir. Three of these occurred following the addition of a NSAID to tenofovir therapy. In the first report, a patient maintained on tenofovir for 29 months developed acute renal failure and acute tubular necrosis requiring dialysis 5 days after beginning indomethacin (100 mg rectally twice daily). In the second report, a patient maintained on tenofovir for 7 months developed acute renal failure and acute tubular necrosis after taking 90 tablets of naproxen (375 mg) over 2 months. The patient died. In the third report, a patient maintained on tenofovir for over a year developed acute renal failure and nephrotic syndrome after 2 months of valdecoxib (20 mg daily) therapy. Symptoms subsided following discontinuation of valdecoxib.(1)

Selected Nsaids/Aspirin (For Cardioprotection)

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Some non-steroidal anti-inflammatory agents (NSAIDs) are reversible inhibitors of cyclooxygenase and aspirin is an irreversible inhibitor. If these NSAIDs are given before aspirin, the aspirin will not be able to bind to the cyclooxygenase site, which will result in a lack of effect.

CLINICAL EFFECTS: The antiplatelet and cardioprotective effect of aspirin may be decreased with the concurrent use of some NSAIDs, particularly during the washout period of the NSAID.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Consideration should be given to use of an NSAID that does not interfere with the antiplatelet effect of aspirin, or a non-NSAID analgesic if appropriate. If an NSAID must be used, cardioprotective doses of aspirin should be administered before taking any NSAIDs. Single doses of ibuprofen should be given at least 8 hours before or at least 2 hours after immediate release aspirin. The administration of other NSAIDs should be separated from aspirin by at least 2 hours.

DISCUSSION: The cardioprotective effect from aspirin is based on the antiplatelet effects. The irreversible inhibition of cyclooxygenase mediates the antiplatelet effects. Administration of a reversible inhibitor or cyclooxygenase blocks the irreversible effect of aspirin on the platelets. This effect has been seen with celecoxib, flufenamic acid, ibuprofen, indomethacin, naproxen, nimesulide, oxaprozin, piroxicam, and tiaprofenic acid but not with diclofenac, etoricoxib, ketorolac, meloxicam, or sulindac. In a study of 80 healthy volunteers, aspirin antiplatelet activity, measured by % thromboxane B2 inhibition (TxB2), was decreased when naproxen 220 mg daily was given simultaneously with or 30 minutes before aspirin 81 mg daily for 10 days (98.7% aspirin alone vs 93.1% and 87.7% naproxen and aspirin). The interaction persisted at least 1 day following discontinuation of naproxen but was normalized by the 3rd day. In a nationwide cohort study, patients were evaluated for thromboembolic cardiovascular and clinically relevant bleeding events with concurrent antithrombotic and ongoing NSAID treatment. A total of 108,232 patients were followed for a mean of 2.3 +/- 1.8 years after diagnosis of myocardial infarction. Concomitant NSAID treatment significantly increased the risk for cardiovascular events (hazard ratio (HR) 6.96; 95% CI 6.24 - 6.77; p<0.001) and bleeding events (HR 4.08; 95% CI 3.51 - 4.73; p<0.001) compared to no NSAID treatment. NSAIDs were further evaluated and revealed the use of celecoxib (HR: 4.65; 95% CI: 3.17 to 6.82; p < 0.001, and 3.44; 95% CI: 2.20 to 5.39; p < 0.001, respectively) and meloxicam (HR: 3.03; 95% CI: 1.68 to 5.47; p < 0.001, and 2.80; 95% CI: 1.40 to 5.60; p < 0.001, respectively) had the lowest risk for cardiovascular and bleeding events, receptively.

Selected Nsaids/Probenecid

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Probenecid may inhibit the renal tubular secretion of some NSAIDs. Probenecid may also prevent biliary clearance of NSAIDs.

CLINICAL EFFECTS: The decreased clearance of NSAIDs may lead to increased blood levels and an increase in adverse effects.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Patients receiving concurrent therapy should be monitored for an increase in NSAID-related adverse effects, including renal insufficiency. The dose of the NSAID may need to be decreased or probenecid may need to be discontinued.

DISCUSSION: Probenecid has been reported to increase the blood levels of indomethacin by 2-fold to 6-fold.(1,2) Probenecid has been reported to increase levels of oral ketoprofen by 93%;(3) however, no effect was seen on intramuscular ketoprofen in another study.(4) Probenecid has also been shown to increase naproxen levels.(5) Probenecid has been shown to increase the maximum concentration (Cmax) of tenoxicam. No other pharmacokinetic parameters were affected.(6) This interaction may result in clinical benefits in some patients.

Selected Nsaids/Selected Cyp2c9 Inhibitors

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: The major metabolic pathway for many non-steroidal anti-inflammatory agents (NSAIDs) is CYP2C9. Inhibitors of CYP2C9 include: amiodarone, asciminib, diosmin, fluconazole, ketoconazole, miconazole, nitisinone, oxandrolone, piperine, voriconazole, and zafirlukast.(1,2)

CLINICAL EFFECTS: Concurrent use of NSAIDs with inhibitors of CYP2C9 may result in increased levels of and adverse effects from NSAIDs, including increased risk for bleeding. NSAIDs linked to this monograph are celecoxib, diclofenac, flurbiprofen, ibuprofen, meloxicam, naproxen, parecoxib, piroxicam and valdecoxib.

PREDISPOSING FACTORS: Higher doses of either agent would be expected to increase the risk for serious adverse effects such as gastrointestinal bleeding (GIB) or renal failure. Patients who smoke, are elderly, debilitated, dehydrated, have renal impairment, or who have a history of GIB due to NSAIDs are also at increased risk for serious adverse events.(3-7) The risk for bleeding episodes may be greater in patients with disease-associated factors (e.g. thrombocytopenia). Drug associated risk factors include concurrent use of multiple drugs which inhibit anticoagulant/antiplatelet metabolism and/or have an inherent risk for bleeding (e.g. NSAIDs).

PATIENT MANAGEMENT: Patients on routine NSAID therapy when an inhibitor of CYP2C9 is started should be evaluated for patient-specific risk factors for NSAID toxicity. Based upon this risk assessment, consider dose reduction of the NSAID or close monitoring for adverse effects. For a patient already receiving a CYP2C9 inhibitor when an NSAID is started, consider initiating the NSAID at a lower than usual dose, particularly when predisposing risk factors for harm are present. The manufacturer of celecoxib recommends that celecoxib be introduced at the lowest recommended dose in patients receiving fluconazole therapy.(3) The manufacturer of fluconazole states that half the dose of celecoxib may be necessary when fluconazole is added.(4) It would be prudent to follow this recommendation with other CYP2C9 inhibitors and to decrease the dose of celecoxib in patients in whom CYP2C9 inhibitors are added to celecoxib therapy. The manufacturer of diclofenac-misoprostol states that the total daily dose of diclofenac should not exceed the lowest recommended dose of 50 mg twice daily in patients taking CYP2C9 inhibitors.(5) It would be prudent to use the lowest recommended dose of other diclofenac formulations in patients taking CYP2C9 inhibitors. The manufacturer of parecoxib states that the dose of parecoxib should be reduced in those patients who are receiving fluconazole therapy.(6) It would be prudent to follow this recommendation with other CYP2C9 inhibitors. The manufacturer of nitisinone recommends reducing the dosage of a CYP2C9 substrate by one-half.(7) If concurrent therapy is warranted, monitor patients receiving concurrent therapy for signs of blood loss, including decreased hemoglobin, hematocrit, fecal occult blood, and/or decreased blood pressure and promptly evaluate patients with any symptoms. When applicable, perform agent-specific laboratory test (e.g. INR, aPTT) to monitor efficacy and safety of anticoagulation. Discontinue anticoagulation in patients with active pathologic bleeding. Instruct patients to report any signs and symptoms of bleeding, such as unusual bleeding from the gums or nose; unusual bruising; red or black, tarry stools; red, pink or dark brown urine; acute abdominal or joint pain and/or swelling.

DISCUSSION: The concomitant administration of celecoxib and fluconazole (200 mg daily) resulted in a 2-fold increase in celecoxib plasma concentration.(3) In vitro studies in human hepatocytes found that amiodarone inhibited diclofenac metabolism.(8) In two separate studies, single doses of diclofenac (50 mg) or ibuprofen (400 mg) were coadministered with the last dose of voriconazole (400 mg q12h on Day 1, followed by 200 mg q12h on Day 2). Voriconazole increased the mean AUC of diclofenac by 78% and increased the AUC of the active isomer of ibuprofen by 100%.(9-11) Coadministration of diosmin increased diclofenac levels by 63%.(2) Coadministration of flurbiprofen or ibuprofen with fluconazole increased the AUC of flurbiprofen by 81% and of the active ibuprofen by 82% compared with either agent alone.(4) Concurrent voriconazole increased meloxicam AUC by 47%.(12,13) The concurrent administration of fluconazole and parecoxib resulted in increases in the area-under-curve (AUC) and maximum concentration (Cmax) of valdecoxib (the active metabolite of parecoxib) by 62% and 19%, respectively.(6) In a study, single dose diclofenac (50mg) given concurrently with the last dose of voriconazole (400 mg every 12 hours on Day 1, 200 mg every 12 hours on Day 2) increased Cmax and AUC by 2.1-fold and 1.8-fold, respectively. (5) Inhibitors of CYP2C9 include: amiodarone, asciminib, camizestrant, diosmin, fluconazole, ketoconazole, miconazole, nitisinone, oxandrolone, piperine, voriconazole, and zafirlukast.(1,2)

Selected Nsaids/Triamterene; Amiloride

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: The exact mechanism is unknown; however, nonsteroidal anti-inflammatory (NSAID) inhibition of prostaglandins may allow triamterene or amiloride- induced nephrotoxicity or hyperkalemia to occur in some patients.

CLINICAL EFFECTS: Possible renal failure or hyperkalemia.

PREDISPOSING FACTORS: Preexisting renal impairment.

PATIENT MANAGEMENT: When possible, avoid concurrent therapy with triamterene or amiloride with NSAIDs. If these agents are used concurrently, monitor renal function and serum electrolytes. If decreased renal function or hyperkalemia develops, discontinue both agents.

DISCUSSION: Acute renal failure and hyperkalemia have been reported in patients receiving concurrent therapy with therapeutic doses of triamterene or amiloride with NSAIDs. Although a majority of these reports have involved indomethacin, other NSAIDs have been implicated (diclofenac, flurbiprofen, and ibuprofen).

Selected Nsaids; Aspirin/Ssris; Snris

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Serotonin release by platelets plays a role in hemostasis.(1,2) The increased risk of bleeding may be a result of a decrease in serotonin reuptake by platelets.

CLINICAL EFFECTS: Concurrent use of a selective serotonin reuptake inhibitor(1-7,13) or a serotonin-norepinephrine reuptake inhibitor(8-10) and a NSAID may result in bleeding.

PREDISPOSING FACTORS: The risk for bleeding episodes may be greater in patients with multiple disease-associated factors (e.g. thrombocytopenia, advanced liver disease). Drug associated risk factors include concurrent use of multiple drugs which inhibit anticoagulant/antiplatelet metabolism and/or have an inherent risk for bleeding (e.g., anticoagulants, antiplatelets, or corticosteroids. Risk of GI bleed may be increased in patients who are of older age, in poor health status, or who use alcohol or smoke. Risk may also be increased with longer duration of NSAID use and prior history of peptic ulcer disease and/or GI bleeding. Renal impairment has been associated with an elevated risk of GI bleed in patients on SSRIs.(15)

PATIENT MANAGEMENT: Selective serotonin reuptake inhibitors(1-7,13) or serotonin-norepinephrine reuptake inhibitors(8-10) and NSAIDs should be used concurrently with caution. Patients should be warned about the increased risk of bleeding and be educated about signs and symptoms of bleeding.(1-11,13) If concurrent therapy is warranted, monitor patients receiving concurrent therapy for signs of blood loss, including decreased hemoglobin, hematocrit, fecal occult blood, and/or decreased blood pressure and promptly evaluate patients with any symptoms. Discontinue anti-platelet agents in patients with active pathologic bleeding. Instruct patients to report any signs and symptoms of bleeding, such as unusual bleeding from the gums or nose; unusual bruising; red or black, tarry stools; red, pink or dark brown urine; acute abdominal or joint pain and/or swelling.

DISCUSSION: In a retrospective review of 5 years of data from the Pharmaco-Epidemiologic Prescription Database, hospitalizations for upper gastro-intestinal bleeding in antidepressant users were compared to those in non-antidepressant users. The risk of a bleed in a patient using an NSAID only based on an observed-expected ratio was 4.5 and in a patient using low-dose aspirin only was 2.5. Concurrent use of a selective serotonin reuptake inhibitor with NSAIDs or low-dose aspirin increased the risk of bleeding to 12.2 and 5.2, respectively.(11) In another study, there were 16 cases of upper gastrointestinal bleeding in patients receiving concurrent therapy with selective serotonin reuptake inhibitors and NSAIDs. Adjusted relative risk of bleeding with NSAIDs, selective serotonin reuptake inhibitors, or both were 3.7, 2.6, or 15.6, respectively.(12)

Selected Nsaids; Salicylates/Ace Inhibitors

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: NSAIDs inhibit prostaglandin synthesis which can lead to afferent arteriolar vasoconstriction and decreased renal blood flow. ACE inhibitors can cause vasodilation of the efferent renal arteriole which may result in decreased glomerular filtration rate.

CLINICAL EFFECTS: Concurrent use of ACE inhibitors with NSAIDs may result in decreased antihypertensive effects. In patients with existing renal impairment, the use of these agents together may also result in further deterioration of renal clearance caused by renal hypoperfusion. Concurrent use of ACE inhibitors with NSAIDs and diuretics may result in increased risk of acute kidney injury (AKI).

PREDISPOSING FACTORS: Low water intake/dehydration, drug sensitivity, greater than 75 years of age, and renal impairment may increase an individuals susceptibility to AKI.

PATIENT MANAGEMENT: Patients maintained on ACE inhibitors should be monitored for a loss of blood pressure control and a change in renal function if an NSAID is added to their regimen. Patients receiving concurrent therapy may require higher doses of ACE inhibitors. If blood pressure control cannot be achieved or if the patient's renal function deteriorates, the NSAID may need to be discontinued. Patients should be monitored for hypotension if NSAIDs are withdrawn from concurrent ACE inhibitor therapy. Concurrent use of ACE inhibitors with NSAIDs and diuretics should be used with caution and monitored closely for signs of AKI.

DISCUSSION: In a computational study, the risk of AKI using triple therapy (combination of a diuretic, renin-angiotensin system (RAS) inhibitor, and NSAID) was assessed. The study found the following factors may increase an individual's susceptibility to AKI: low water intake, drug sensitivity, greater than 75 years of age, and renal impairment.(30,31) In an observational study, current use of a triple therapy combination was associated with an increased rate of acute kidney injury (rate ratio (RR) 1.31, 95% confidence interval (CI) 1.12-1.53). The highest risk of AKI associated with triple therapy were observed in the first 30 days of use (RR 1.82, CI 1.35-2.46).(32) Indomethacin has been shown to inhibit the antihypertensive effect of captopril, cilazapril, enalapril, losartan, perindopril, and valsartan. Ibuprofen has been shown to decrease the antihypertensive effects of captopril. Two separate case reports describe individuals suspected of ACEI-associated angioedema precipitated by NSAIDs. Both cases reported symptom resolution after cessation of the NSAID. Studies have shown that sulindac does not affect the antihypertensive effects of captopril and enalapril. One or more of the drug pairs linked to this monograph have been included in a list of interactions that could be considered for classification as "non-interruptive" in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology.

*Ibuprofen is contraindicated in patients with known hypersensitivity (e.g., anaphylaxis, serious dermatologic reactions) to the drug or any ingredient in the formulation.

*Nonsteroidal anti-inflammatory agents (NSAIAs) generally are contraindicated in patients in whom asthma, urticaria, or other sensitivity reactions are precipitated by aspirin or other NSAIAs, since there is potential for cross-sensitivity between NSAIAs and aspirin, and severe, potentially fatal, bronchospasm can occur in such patients.

*NSAIAs are contraindicated in the setting of coronary artery bypass graft (CABG) surgery.

Contraindications with IV Ibuprofen Lysine for PDA

*Neonates with proven or suspected untreated infection.

*Neonates with active bleeding, such as those with intracranial hemorrhage or GI bleeding, and in neonates with thrombocytopenia or underlying coagulation defect.

*Neonates with suspected necrotizing enterocolitis.

*Neonates with substantially impaired renal function.

*Neonates with congenital heart disease when patency of the ductus arteriosus is necessary for adequate pulmonary or systemic blood flow (e.g., neonates with pulmonary atresia, severe tetralogy of Fallot, or severe coarctation of the aorta).

• Aspirin exacerbated respiratory disease
• Cerebrovascular accident
• History of roux-en-Y gastric bypass
• Post-operative from CABG surgery
• Pregnancy
• Renal transplant

• Acute myocardial infarction
• Alcohol use disorder
• Chronic kidney disease stage 3A (moderate) GFR 45-59 ml/min
• Chronic kidney disease stage 3B (moderate) GFR 30-44 ml/min
• Chronic kidney disease stage 4 (severe) GFR 15-29 ml/min
• Chronic kidney disease stage 5 (failure) GFr<15 ml/min
• CYp2c9 intermediate metabolizer (activity score 1)
• CYp2c9 poor metabolizer
• Gastric cancer
• Gastrointestinal perforation
• Gastrointestinal ulcer
• Hemorrhage
• History of kidney donation
• Increased risk of bleeding
• Nephrectomy
• Systemic mastocytosis
• Thrombotic disorder

• Chronic heart failure
• Disease of liver
• Hypertension
• Kidney disease with likely reduction in glomerular filtration rate (GFr)
• Tobacco smoker

Adverse effects reported in at least 5% of adults receiving IV ibuprofen include nausea, flatulence, vomiting, headache, hemorrhage, and dizziness.

Adverse effects reported in at least 2% of pediatric patients receiving IV ibuprofen include infusion site pain, vomiting, nausea, anemia, and headache.

The most common type of adverse effect occurring with ibuprofen tablets is GI, and was reported in 4-16% of patients in clinical studies.

Adverse effects occurring in 1-10% of patients receiving ibuprofen oral suspension include abnormal renal function, anemia, dizziness, edema, elevated transaminases, fluid retention, GI effects (e.g., abdominal pain, bloating, constipation, diarrhea, dyspepsia, epigastric pain, flatulence, heartburn, nausea, vomiting), headaches, increased bleeding times, nervousness, pruritis, rashes (including maculopapular), and tinnitus.

Adverse effects occurring in at least 10% of premature infants receiving IV ibuprofen lysine for the treatment of patent ductus arteriosus (PDA) include sepsis, anemia, intraventricular bleeding, apnea, GI disorders, impaired renal function, respiratory infection, skin lesions, hypoglycemia, hypocalcemia, and respiratory failure.

More Frequent

• Skin rash

Less Frequent

• Body fluid retention
• Edema
• Pruritus of skin
• Tinnitus

Rare or Very Rare

• Abnormal hepatic function tests
• Abnormal hepatic function tests
• Abnormal vaginal bleeding
• Acute cognitive impairment
• Acute myocardial infarction
• Acute pancreatitis
• Agranulocytosis
• Agranulocytosis
• Allergic dermatitis
• Altered mental status
• Anaphylaxis
• Anaphylaxis
• Anemia
• Anemia
• Angioedema
• Angioedema
• Aphthous stomatitis
• Aplastic anemia
• Atrioventricular block
• Bloody stools
• Bloody vomit
• Blurred vision
• Bronchospastic pulmonary disease
• Bronchospastic pulmonary disease
• Bullous dermatitis
• Cardiac arrhythmia
• Cardiac arrhythmia
• Cerebrovascular accident
• Chest pain
• Chest tightness
• Chronic heart failure
• Conjunctivitis
• Cystitis
• Depression
• Diplopia
• DRESS syndrome
• Drug-induced hepatitis
• Dry eye
• Dyspnea
• Dyspnea
• Eosinophilia
• Epistaxis
• Erythema multiforme
• Esophageal ulcer
• Exfoliative dermatitis
• Gastric ulcer
• Gastritis
• Gastrointestinal hemorrhage
• Gastrointestinal perforation
• Gastrointestinal ulcer
• Hallucinations
• Hematuria
• Hemolytic anemia
• Hepatitis
• Hepatitis
• Hyperkalemia
• Hypertension
• Hypotension
• IgA vasculitis
• Increased alanine transaminase
• Increased aspartate transaminase
• Interstitial pneumonitis
• Jaundice
• Kidney disease with reduction in glomerular filtration rate (GFr)
• Laryngeal edema
• Leukopenia
• Leukopenia
• Lupus-like syndrome
• Mood changes
• Nephrotoxicity
• Neutropenic disorder
• Non-infective meningitis
• Obstructive hyperbilirubinemia
• Pancytopenia
• Pancytopenia
• Peptic ulcer
• Peripheral neuropathy
• Polyuria
• Psychiatric disorder
• Renal failure
• Renal papillary necrosis
• Renal tubular necrosis
• Rhabdomyolysis
• Rhinitis
• Scotomata
• Seizure disorder
• Serum sickness
• Skin rash
• Stevens-johnson syndrome
• Stevens-johnson syndrome
• Thrombocytopenic disorder
• Thrombocytopenic disorder
• Toxic amblyopia
• Toxic epidermal necrolysis
• Toxic epidermal necrolysis
• Urticaria
• Urticaria
• Vasculitis
• Visual changes
• Wheezing
• Worsening of chronic heart failure

More Frequent

• Constipation
• Diarrhea
• Dizziness
• Dizziness
• Headache disorder
• Heartburn
• Nausea

Less Frequent

• Acute abdominal pain
• Anorexia
• Constipation
• Diarrhea
• Dyspepsia
• Flatulence
• Gastric acid hypersecretory conditions
• Headache disorder
• Irritability
• Musculoskeletal pain
• Nervousness
• Vomiting

Rare or Very Rare

• Acne vulgaris
• Acute abdominal pain
• Acute cognitive impairment
• Agitation
• Allergic conjunctivitis
• Alopecia
• Anorexia
• Anticholinergic toxicity
• Arthralgia
• Cramps
• Delirium
• Drowsy
• Drowsy
• Dry skin
• Dysgeusia
• Ecchymosis
• Facial edema
• Fatigue
• Fever
• Flushing
• Flushing
• General weakness
• Hallucinations
• Hearing loss
• Insomnia
• Insomnia
• Lethargy
• Mouth irritation
• Nausea
• Palpitations
• Paresthesia
• Pruritus of skin
• Skin photosensitivity
• Symptoms of anxiety
• Tachycardia
• Tinnitus
• Vomiting
• Xerostomia
• Xerostomia

No enhanced messaging available.

The manufacturers state that the safety and efficacy of oral ibuprofen in children <6 months of age have not been established.

Pediatric patients receiving ibuprofen dosages exceeding 30 mg/kg daily and those who have had abnormal liver function test results associated with prior NSAIA therapy should be carefully monitored for signs and symptoms of early liver dysfunction.

Safety and efficacy of IV ibuprofen have been established for treatment of pain and fever in pediatric patients 3 months of age and older. Use of IV ibuprofen for these indications is supported by evidence from one open-label and acetaminophen-controlled study of fever, as well as additional safety data from four studies in 164 pediatric patients, supportive pediatric data from other approved ibuprofen preparations, and evidence from adequate and well-controlled studies in adults. The most common adverse effects of IV ibuprofen in pediatric patients are infusion site pain, vomiting, nausea, anemia, and headache. Efficacy of IV ibuprofen for relief of pain or reduction of fever has not been established in pediatric patients <3 months of age.

Long-term follow-up (beyond a postconceptional age of 36 weeks) of premature neonates receiving ibuprofen lysine for patent ductus arteriosus (PDA) has not been conducted. The effects of ibuprofen on neurodevelopmental outcome, growth, and other complications of prematurity (e.g., retinopathy of prematurity, chronic lung disease) have not been assessed.

Safety and efficacy of ibuprofen lysine have been established only in premature infants.

Use of NSAIAs during pregnancy at about 30 weeks' gestation or later can cause premature closure of the fetal ductus arteriosus, and use at about 20 weeks' gestation or later has been associated with fetal renal dysfunction resulting in oligohydramnios and, in some cases, neonatal renal impairment. Because of these risks, use of NSAIAs should be avoided in pregnant women at about 30 weeks' gestation or later; if NSAIA therapy is necessary between about 20 and 30 weeks' gestation, the lowest effective dosage and shortest possible duration of treatment should be used. Monitoring of amniotic fluid volume via ultrasound examination should be considered if the duration of NSAIA treatment exceeds 48 hours; if oligohydramnios occurs, the drug should be discontinued and follow-up instituted according to clinical practice. Pregnant women should be advised to avoid use of NSAIAs beginning at 20 weeks' gestation unless otherwise advised by a clinician; they also should be informed that NSAIAs should be avoided beginning at 30 weeks' gestation because of the risk of premature closure of the fetal ductus arteriosus and that monitoring for oligohydramnios may be necessary if NSAIA therapy is required for longer than 48 hours' duration between about 20 and 30 weeks of gestation.

Fetal renal dysfunction resulting in oligohydramnios and, in some cases, neonatal renal impairment has been observed, on average, following days to weeks of maternal NSAIA use, although oligohydramnios has been observed infrequently as early as 48 hours after initiation of NSAIA therapy. Oligohydramnios is often, but not always, reversible following discontinuance of NSAIA therapy. Complications of prolonged oligohydramnios may include limb contracture and delayed lung maturation. A limited number of case reports have described maternal NSAIA use and neonatal renal dysfunction, in some cases irreversible, without oligohydramnios. Some cases of neonatal renal dysfunction have required treatment with invasive procedures such as exchange transfusion or dialysis. Methodologic limitations of these postmarketing studies and case reports include lack of a control group; limited information regarding dosage, duration, and timing of drug exposure; and concomitant use of other drugs. These limitations preclude establishing a reliable estimate of the risk of adverse fetal and neonatal outcomes with maternal NSAIA use. Available data on neonatal outcomes generally involved preterm infants, and the extent to which certain reported risks can be generalized to full-term infants is uncertain.

Animal data indicate that prostaglandins have an important role in endometrial vascular permeability, blastocyst implantation, and decidualization. In animal studies, inhibitors of prostaglandin synthesis, such as ibuprofen, were associated with increased preimplantation and postimplantation losses. Prostaglandins also have an important role in fetal kidney development. In animal studies, inhibitors of prostaglandin synthesis impaired kidney development at clinically relevant doses.

There are no adequate and well-controlled studies of ibuprofen in pregnant women. In animal reproduction studies, no clear developmental effects were observed in rabbits or rats given ibuprofen throughout the gestational period at dosages up to 0.4 or 0.5 times, respectively, the maximum recommended human dosage (MRHD). An increase in membranous ventricular septal defects was reported in rats given ibuprofen on gestation days 9 and 10 at a dosage of 0.8 times the MRHD.

The effects of ibuprofen on labor and delivery are unknown. In studies in rats, drugs that inhibit prostaglandin synthesis, including NSAIAs, delayed parturition and increased the incidence of stillbirth.

Reproduction studies in rats and rabbits using oral famotidine dosages up to 2 (approximately 2500 times the maximum human dosage) and 0.5 g/kg daily, respectively, or IV dosages up to 0.2 (approximately 250 times the maximum human dosage) and 0.1 g/kg daily, respectively, have not revealed evidence of harm to the fetus. Oral dosages of 2 g/kg daily inhibited weight gain in pregnant rats, and those of 0.5 and/or 2 g/kg daily on days 7-17 of gestation decreased fetal weight and delayed sternal ossification in the offspring. Decreased food intake and decreased weight gain also occurred in offspring of rats receiving these dosages from days 10-28 post partum. Death and locomotor dysfunction were observed in pregnant rats receiving IV famotidine dosages of 100 or 200 mg/kg daily. IV dosages of 100 or 200 mg/kg daily in rats have decreased pup body weight during the post-weaning period. Although no direct fetotoxic effects have been observed, sporadic abortions and decreases in fetal weight occurred secondary to substantial decreases in food intake in pregnant rabbits receiving oral dosages of 200 mg/kg (250 times the usual human dosage) or more daily. Decreased number of sacrocaudal vertebrae and delayed ossification have occurred in rabbits receiving oral famotidine dosages of 0.5 g/kg daily. There are no adequate and controlled studies to date using famotidine in pregnant women, and the drug should be used during pregnancy only when clearly needed. Women who are pregnant or nursing should seek the advice of a health professional before using famotidine for self-medication.

Limited data indicate that ibuprofen is distributed into milk, resulting in infant exposures of 0.06-0.6% of the maternal weight-adjusted daily dosage. Adverse effects on breast-fed infants or effects on milk production have not been reported to date. The developmental and health benefits of breast-feeding should be considered along with the mother's clinical need for ibuprofen and any potential adverse effects on the breast-fed infant from the drug or from the underlying maternal condition.

Famotidine is distributed into milk in humans and in animals. The drug has produced transient growth depression in the offspring of lactating rats receiving dosages at least 600 times the usual human dosage. Because of the potential for serious adverse reactions to famotidine in nursing infants, a decision should be made whether to discontinue nursing or the drug, taking into account the importance of the drug to the woman.

The manufacturers make no specific dosage recommendations in geriatric patients; however, geriatric patients are generally at a greater risk for NSAIA-associated serious cardiovascular, GI, and/or renal adverse effects. If the expected benefits outweigh the potential risks of therapy, initiate at the lower end of the dosage range and monitor for adverse effects.

Geriatric patients are at increased risk for NSAIA-associated serious adverse cardiovascular, GI, and renal effects. Many of the spontaneous reports of fatal adverse GI effects in patients receiving NSAIAs involve geriatric individuals. If the anticipated benefits of ibuprofen therapy outweigh the potential risks, ibuprofen should be initiated at the lower end of the dosing range and patients should be monitored for adverse effects.

Clinical studies of IV ibuprofen did not include sufficient numbers of patients >=65 years of age to determine whether geriatric patients respond differently than younger adults. Dosage should be selected with caution, starting at the low end of the dosage range, because of the greater frequency of decreased hepatic, renal, and/or cardiac function and concomitant disease and drug therapy observed in the elderly.