Fiber Gummies-Vitamin D3 (inulin/cholecalciferol (vit D3))

Bulk-forming laxatives are usually administered 1-3 times daily. To reduce the risk of esophageal obstruction in patients receiving large (e.g., the maximum daily dosage recommended by the manufacturer) dosages of bulk-forming laxatives, these laxatives should be administered in divided doses instead of a single daily dose. The usual dosages for the individual bulk-forming laxatives are below; for dosages in children younger than the ages listed, a physician should be consulted.

Dietary intake of ergocalciferol and cholecalciferol varies among individual patients, and dietary intake should always be considered when calculating the appropriate dosage of vitamin D analogs. During therapy with vitamin D analogs, dosage depends on the nature and severity of the patient's hypocalcemia and must be individualized to maintain serum calcium concentrations of 9-10 mg/dL. In the management of hypoparathyroidism, pseudohypoparathyroidism, and familial hypophosphatemia, the range between therapeutic and toxic effects is narrow; however, hypercalcemia may occur at any time when therapeutic doses of vitamin D analogs are used, and careful monitoring is imperative. In the management of secondary hyperparathyroidism, dosage of vitamin D analogs should be individualized according to serum or plasma intact parathyroid hormone (iPTH) concentrations and serum calcium and phosphorus concentrations.

During therapy with vitamin D analogs, patients should receive adequate amounts of calcium through management of diet or administration of calcium supplements; however, overdosage of calcium may lead to hypercalcemia. Dosage of vitamin D analogs should be decreased when symptoms improve and before biochemical normality or complete bone healing has occurred because requirements for vitamin D analogs often decrease after bone healing occurs. In patients who become bedridden (especially children), dosage reduction may occasionally be needed to avoid hypercalcemia.

Bulk-forming laxatives are administered orally. Commercially available powders, flakes, granules, tablets, and liquids should be dissolved and/or diluted according to the instructions of the manufacturer. In the treatment of constipation, at least one full glass (250 mL) of liquid should be administered with each laxative dose. When used to increase the bulk of stools in patients with chronic, watery diarrhea, one manufacturer suggests that one-third of a glass (80 mL) of liquid be administered with each dose.

Vitamin D analogs are usually administered orally; however, calcitriol, doxercalciferol, and paricalcitol may be given by IV injection. Ergocalciferol may be given by IM injection; however, a suitable formulation of the drug for IM injection no longer is commercially available in the US.

No dosing information is available for this tab.

No dosing information is available for this tab.

There is no enhanced messaging for this drug.

There are no contraindication interactions for this drug.

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

Laxatives/Trofinetide

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

MECHANISM OF ACTION: Trofinetide commonly causes diarrhea of mild to moderate severity. Laxatives may increase the incidence or severity of diarrhea.(1)

CLINICAL EFFECTS: Concurrent use of laxatives with trofinetide may increase the risk of severe diarrhea.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Patients should stop laxatives before starting trofinetide. If diarrhea occurs, consider anti-diarrheal treatment and monitor hydration status. If severe diarrhea or dehydration occurs, interrupt, reduce dose, or discontinue trofinetide.(1)

DISCUSSION: In clinical trials, 85% of patients on trofinetide developed diarrhea. Concurrent use of laxatives may increase this risk.(1)

Laxatives; Stool Softeners/Tenapanor

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

MECHANISM OF ACTION: Tenapanor commonly causes diarrhea of mild to moderate severity. Laxatives and stool softeners may increase the incidence or severity of diarrhea.(1)

CLINICAL EFFECTS: Concurrent use of laxatives or stool softeners with tenapanor may increase the risk of severe diarrhea.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: The US manufacturer of tenapanor states that patients should be instructed to avoid stool softeners and laxatives with tenapanor. If severe diarrhea occurs, tenapanor should be discontinued.(1)

DISCUSSION: In clinical trials, 43-53% of CKD patients on dialysis treated with tenapanor developed diarrhea. Diarrhea usually occurred soon after treatment initiation and was severe in 5% of patients.(1)

Serum Phosphate Level-Altering Drugs/Erdafitinib

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

MECHANISM OF ACTION: Medications that alter serum phosphate may interfere with interpretation of phosphate levels that are needed to determine initial erdafitinib dose.(1)

CLINICAL EFFECTS: Serum phosphate levels that are elevated by concomitant medications may result in an inappropriately low dose and decreased effectiveness of erdafitinib. Serum phosphate levels that are decreased by concomitant medications may result in an inappropriately high dose and increased toxicity from erdafitinib.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: The manufacturer of erdafitinib states that agents that alter serum phosphate levels should be avoided before the initial dose increase period for erdafitinib based on serum phosphate levels (days 14 to 21).(1)

DISCUSSION: Concomitant administration of serum phosphate level-altering agents during the initial dose increase period of erdafitinib based on serum phosphate levels (days 14 to 21) may interfere with serum phospate levels and lead to incorrect dosing of erdafitinib.(1) Agents that may alter serum phosphate levels linked to this monograph include: aluminum carbonate, aluminum hydroxide, calcium acetate, calcium carbonate, calcium citrate, cod liver oil, ferric citrate, lanthanum, magnesium carbonate, magnesium hydroxide, potassium phosphate, sevelamer, sodium phosphate, sucroferric oxyhydroxide, tenapanor, and vitamin D.(1)

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

Bulk Forming Laxatives/Clozapine

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

MECHANISM OF ACTION: Clozapine has potent anticholinergic properties and inhibits serotonin receptors, including 5-HT3.(1-4) Both of these properties may cause inhibition of gastrointestinal (GI) smooth muscle contraction, resulting in decreased peristalsis.(3,4) If fluid intake is inadequate, bulk forming laxatives can increase the risk of gastrointestinal obstruction.(1-6)

CLINICAL EFFECTS: Concurrent use of clozapine and bulk forming laxatives with inadequate fluid intake may increase the risk of constipation (common) and serious bowel complications (uncommon), including complete bowel obstruction, fecal impaction, paralytic ileus and intestinal ischemia or infarction.(1-6)

PREDISPOSING FACTORS: The risk for serious bowel complications is higher with increasing age, higher frequency of constipation, and in patients on higher doses of clozapine or multiple anticholinergic agents.(1,5)

PATIENT MANAGEMENT: Concurrent use of bulk forming laxatives with clozapine may be used with caution in patients who can maintain adequate fluid intake. Evaluate the patient's bowel function regularly. If patient is unable to maintain adequate fluid intake and use bulk forming laxatives as prescribed, avoid the use of bulk forming laxatives with clozapine.(1-6) Monitor for symptoms of constipation and GI hypomotility, including having bowel movements less than three times weekly or less than usual, difficulty having a bowel movement or passing gas, nausea, vomiting, and abdominal pain or distention.(2) Consider a prophylactic laxative in those with a history of constipation or bowel obstruction.(2) Review patient medication list for anticholinergic agents which may have additive effects on decreased GI motility. When possible, decrease the dosage or number of prescribed anticholinergic agents, particularly in the elderly. Counsel the patient about the importance of maintaining adequate hydration. Encourage regular exercise and eating a high-fiber diet.(2)

DISCUSSION: The concurrent use of clozapine and bulk forming laxatives has not been studied. Use of bulk forming laxatives with inadequate fluid intake has been associated with gastrointestinal obstruction.

Fat Soluble Vitamins/Colesevelam

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

MECHANISM OF ACTION: Colesevelam may decrease the absorption of fat-soluble vitamins A, D, E, and K.(1)

CLINICAL EFFECTS: Colesevelam may reduce absorption of fat soluble vitamins, leading to a deficiency state.

PREDISPOSING FACTORS: A pre-existing deficiency of fat soluble vitamins (A,D,E and K) or chronic malabsorption syndrome.

PATIENT MANAGEMENT: The inhibition of fat soluble vitamin absorption by colesevelam should be borne in mind during implementation of a vitamin supplementation strategy. Oral multivitamin supplements should be taken at least four hours before the dose of colesevelam.(1)

DISCUSSION: Colesevelam may decrease the absorption of fat-soluble vitamins A, D, E, and K.(1)

Fat Soluble Vitamins/Orlistat

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

MECHANISM OF ACTION: The acetate ester forms of vitamin A and vitamin E must undergo hydrolysis for absorption from the gastrointestinal tract.(1) The enzyme responsible for this hydrolysis is inhibited by orlistat.(2)

CLINICAL EFFECTS: Orlistat may reduce absorption of fat soluble vitamins, leading to a deficiency state.

PREDISPOSING FACTORS: A pre-existing deficiency of fat soluble vitamins (A,D,E and K) or chronic malabsorption syndrome.

PATIENT MANAGEMENT: The inhibition of fat soluble vitamin absorption by orlistat should be borne in mind during implementation of a vitamin supplementation strategy. Patients should be strongly encouraged to take a multivitamin supplement which contains fat soluble vitamins, particularly Vitamin D as it appears most susceptible to this interaction.(4,5) Multivitamin supplements should be taken at least two hours before or after the dose of orlistat, or at bedtime.(4) Patients with chronic malabsorption syndromes should not receive orlistat.(4)

DISCUSSION: Adult patients taking orlistat without supplementation showed a greater reduction in vitamin A,D,E and beta-carotene levels compared to placebo during two or more consecutive visits in studies of 1-2 years duration; these patients had normal baseline values prior to orlistat therapy. Low vitamin values in orlistat patients were as follows: low Vitamin D 12%, low beta-carotene 6.1%, low Vitamin E 5.8%, low Vitamin A 2.2%.(4) A pharmacokinetic interaction study showed a 30% reduction in beta-carotene supplement absorption and a 60% decreased in vitamin E acetate absorption with concomitant orlistat.(4) In a study, orlistat produced the vitamin net concentration by approximately 43%.(1) In a study, no statistically significant decrease in vitamin A absorption was observed with concurrent orlistat.(2) In a study, mean vitamin D levels were significantly reduced compared with baseline after one month of orlistat therapy despite multivitamin supplementation.(5)

There is no enhanced messaging for this drug.

• Appendicitis
• Esophageal obstruction
• Gastrointestinal obstruction
• Hypervitaminosis D

• Dysphagia
• Hypercalcemia
• Hyperphosphatemia
• Kidney stone

• Kidney disease with reduction in glomerular filtration rate (GFr)
• Sarcoidosis

There is no enhanced messaging for this drug.

Less Frequent

• Allergic dermatitis
• Esophageal obstruction
• Intestinal impaction
• Pruritus of skin
• Skin rash

There are no less severe adverse reactions for this drug.

No enhanced messaging available.

No enhanced messaging available.

A characteristic physiognomy, possibly with aortic valvular stenosis, retinopathy, and mental and/or physical retardation, has occurred following prolonged hypercalcemia in infants and in neonates of mothers with hypercalcemia during pregnancy. Hypercalcemia during pregnancy may also lead to suppression of PTH concentrations in the neonate resulting in hypocalcemia, tetany, and seizures. Safe use of calcifediol, calcitriol, dihydrotachysterol (no longer commercially available in the US), paricalcitol, or ergocalciferol during pregnancy has not been established; however, the risks to the mother and fetus from untreated hypoparathyroidism or hypophosphatemia may be greater than those resulting from administration of vitamin D analogs.

Safe use of calcifediol, calcitriol, dihydrotachysterol, doxercalciferol, paricalcitol, or ergocalciferol during lactation has not been established; however, the risks to the mother and fetus from untreated hypoparathyroidism or hypophosphatemia may be greater than those resulting from administration of vitamin D analogs. Large doses of vitamin D analogs should not be administered to nursing women.

No enhanced messaging available.