Emtriva (emtricitabine)

Emtricitabine capsules and oral solution are not bioequivalent. Bioavailability of the oral solution is 80% relative to that of the capsule.

Reduce dosage in patients with renal impairment; emtricitabine is principally eliminated by the kidney.

Emtricitabine is administered orally once daily without regard to meals.

Single-entity emtricitabine is commercially available as 200-mg capsules or an oral solution containing 10 mg/mL.

Emtricitabine is also commercially available in the following fixed-combination tablets for oral use: emtricitabine/tenofovir DF (Truvada(R)), efavirenz/emtricitabine/tenofovir DF (Atripla(R)), emtricitabine/rilpivirine/tenofovir DF (Complera(R)), elvitegravir/cobicistat/emtricitabine/tenofovir DF (Stribild(R)), elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide (Genvoya(R)), emtricitabine/rilpivirine/tenofovir alafenamide (Odefsey(R)), emtricitabine/tenofovir alafenamide (Descovy(R)), and bictegravir/emtricitabine/tenofovir alafenamide (Biktarvy(R)). See the full prescribing information for administration of each of these combination products.

Emtricitabine is used in conjunction with other antiretrovirals. Single-entity emtricitabine should not be used concomitantly with any other emtricitabine-containing preparations.

Store capsules at 25degreesC (excursions permitted to 15-30degreesC).

Store oral solution at 2-8degreesC. For patient use, store at 25degreesC (excursions permitted to 15-30degreesC); use within 3 months.

In vitro studies indicate that emtricitabine does not inhibit cytochrome P-450 (CYP) isoenzymes 1A2, 2A6, 2B6, 2C9, 2C19, 2D6, or 3A4. Emtricitabine does not inhibit uridine-5'-disphosphoglucuronyl transferase. The following drug interactions are based on studies using emtricitabine. When a fixed combination containing emtricitabine is used, interactions associated with each drug in the fixed combination should be considered.

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

Anti-Retrovirals/Atidarsagene Autotemcel

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: Atidarsagene autotemcel is prepared from apheresed cells that are transduced with a replication defective, self-inactivating lentiviral vector. Antiretrovirals may interfere with the manufacturing of apheresed cells.

CLINICAL EFFECTS: Use of antiretrovirals before mobilization and apheresis may interfere with the production of atidarsagene autotemcel.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Discontinue antiretrovirals for at least one month prior to mobilization (or the expected duration of time needed for elimination of the medication) until all cycles of apheresis are completed. If a patient requires antiretrovirals for HIV prophylaxis, then confirm a negative HIV test before beginning mobilization and apheresis of CD34+ cells.

DISCUSSION: Antiretroviral medications may interfere with the manufacturing of atidarsagene autotemcel therapy.(1)

Anti-Retrovirals/Elivaldogene Autotemcel

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: Elivaldogene autotemcel is prepared from apheresed cells that are transduced with a replication defective, self-inactivating lentiviral vector. Antiretrovirals may interfere with the manufacturing of apheresed cells.

CLINICAL EFFECTS: Use of antiretrovirals before mobilization and apheresis may interfere with the production of elivaldogene autotemcel.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Discontinue antiretrovirals for at least one month prior to mobilization and until all cycles of apheresis are completed. If a patient requires antiretrovirals for HIV prophylaxis, then confirm a negative HIV test before beginning mobilization and apheresis of CD34+ cells.

DISCUSSION: Antiretroviral medications may interfere with the manufacturing of elivaldogene autotemcel therapy.(1)

Anti-Retrovirals/Etuvetidigene Autotemcel

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: Etuvetidigene autotemcel is prepared from apheresed cells that are transduced with a replication defective, self-inactivating HIV-based lentiviral vector. Antiretrovirals may interfere with the manufacturing of the apheresed cells.

CLINICAL EFFECTS: Use of antiretrovirals before mobilization and apheresis may interfere with the production of etuvetidigene autotemcel.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Patients should not take antiretrovirals for at least one month prior to mobilization and until at least 7 days after etuvetidigene autotemcel infusion.(1) If a patient requires antiretroviral agents for HIV post-exposure prophylaxis, etuvetidigene autotemcel treatment should be delayed until HIV testing is negative at 6 months post-exposure.(1)

DISCUSSION: Antiretroviral medications may interfere with the manufacturing of etuvetidigene autotemcel therapy.(1)

Anti-Retrovirals/Lovotibeglogene Autotemcel

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: Lovotibeglogene autotemcel is prepared from apheresed cells that are transduced with a replication defective, self-inactivating lentiviral vector. Antiretrovirals may interfere with the manufacturing of apheresed cells.

CLINICAL EFFECTS: Use of antiretrovirals before mobilization and apheresis may interfere with the production of lovotibeglogene autotemcel.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Discontinue antiretrovirals for at least one month prior to mobilization and until all cycles of apheresis are completed.(1) There are some long-acting antiretroviral medications that may require a longer duration of discontinuation for elimination of the medication. If a patient is taking anti-retrovirals for HIV prophylaxis, confirm a negative test for HIV before beginning mobilization and apheresis of CD34+ cells.(1)

DISCUSSION: Antiretroviral medications may interfere with the manufacturing of lovotibeglogene autotemcel therapy.(1)

Anti-Retrovirals; Hydroxyurea/Betibeglogene Autotemcel

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: Betibeglogene autotemcel is prepared from apheresed cells that are transduced with a replication defective, self-inactivating lentiviral vector. Antiretrovirals may interfere with the manufacturing of apheresed cells. Hydroxyurea may interfere with hematopoietic stem cell (HSC) mobilization of CD34+ cells.(1)

CLINICAL EFFECTS: Use of hydroxyurea before mobilization may result in unsuccessful stem cell mobilization. Use of antiretrovirals before mobilization and apheresis may interfere with the production of betibeglogene autotemcel.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Discontinue antiretrovirals and hydroxyurea for at least one month prior to mobilization and until all cycles of apheresis are completed. If a patient requires antiretrovirals for HIV prophylaxis, then confirm a negative HIV test before beginning mobilization and apheresis of CD34+ cells.

DISCUSSION: Antiretroviral medications and hydroxyurea may interfere with the manufacturing of betibeglogene autotemcel therapy.(1)

Emtricitabine; Lamivudine/Islatravir

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: Emtricitabine and lamivudine may inhibit the intracellular phosphorylation of islatravir by deoxycytidine kinase (dCK).(1)

CLINICAL EFFECTS: Concurrent administration of emtricitabine or lamivudine with islatravir may result in decreased clinical efficacy of islatravir.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: The manufacturer of the doravirine-islatravir fixed-dose combination states that co-administration with emtricitabine or lamivudine is contraindicated.(1)

DISCUSSION: Islatravir undergoes a series of phosphorylations to its active metabolites.(1) In a clinical study in healthy participants, co-administration of multiple daily doses of 300 mg lamivudine and a single dose of 2 mg islatravir (8 times the recommended dosage) decreased intracellular ISL-TP (islatravir active metabolite) area under the curve (AUC) level by 87% and maximum concentration (Cmax) by 76% relative to islatravir alone. A similar effect is anticipated when islatravir is co-administered with emtricitabine.(1,2) Compounds phosphorylated by dCK and linked to this monograph include: emtricitabine and lamivudine.

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

Anti-Retrovirals/Marnetegragene Autotemcel

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

MECHANISM OF ACTION: Marnetegragene autotemcel is prepared from apheresed cells that are transduced with a replication defective, self-inactivating lentiviral vector. Antiretrovirals may interfere with the manufacturing of transduced cells.

CLINICAL EFFECTS: Use of antiretrovirals before mobilization and apheresis may interfere with the production of marnetegragene autotemcel.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Discontinue antiretrovirals for at least one month prior to mobilization (or the expected duration of time needed for elimination of the antiretrovirals) until all cycles of apheresis are completed. If a patient requires antiretrovirals for HIV prophylaxis, then confirm a negative HIV test before beginning mobilization and apheresis of CD34+ cells.(1)

DISCUSSION: Antiretroviral medications may interfere with the manufacturing of marnetegragene autotemcel.(1)

Deoxycytidine Kinase Substrates/Cladribine Oral

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

MECHANISM OF ACTION: Clofarabine, cytarabine, emtricitabine, fludarabine, gemcitabine, lamivudine, molnupiravir, nelarabine and zalcitabine may inhibit the intracellular phosphorylation of cladribine by deoxycytidine kinase (dCK).

CLINICAL EFFECTS: Concurrent administration of clofarabine, cytarabine, emtricitabine, fludarabine, gemcitabine, lamivudine, molnupiravir, nelarabine, or zalcitabine with cladribine may result in decreased clinical efficacy of cladribine.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: The manufacturer of lamivudine states that the concurrent use of lamivudine and cladribine is not recommended.(1) The manufacturer of cladribine states that concurrent use of compounds that require activation by intracellular phosphorylation should be avoided.(2)

DISCUSSION: Cladribine undergoes a series of phosphorylations to its active metabolites. In a case report, a patient on lamivudine who received cladribine concurrently did not experience a decrease in his lymphocyte count. After discontinuation of lamivudine and readministration of cladribine, his lymphocytes dropped as expected.(3) It is expected that other compounds phosphorylated by dCK would also decrease cladribine's efficacy.(4) Compounds phosphorylated by dCK include: clofarabine, cytarabine, emtricitabine, fludarabine, gemcitabine, lamivudine, molnupiravir, nelarabine and zalcitabine.

Selected Antiretrovirals/Orlistat

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

MECHANISM OF ACTION: The exact mechanism is unknown. Orlistat may reduce the absorption of lipophilic antiretroviral HIV drugs by retention in the gastrointestinal tract or reduced gastrointestinal tract transit time.

CLINICAL EFFECTS: The concurrent administration of orlistat and atazanavir, efavirenz, emtricitabine, maraviroc, ritonavir, or tenofovir may result in a decrease in the levels and clinical effects of the antiretroviral, including loss of virological control.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: HIV RNA levels should be frequently monitored in patients taking orlistat while being treated for HIV infection. If there is a confirmed increase in HIV viral load, orlistat should be discontinued.(1)

DISCUSSION: Loss of virological control has been reported in HIV-infected patients taking orlistat concomitantly with lipophilic antiretroviral drugs.(1) There are three case reports of patients having an increased HIV viral load after taking orlistat concomitantly with their HIV therapy.(2-4) Antiretrovirals included in this monograph are atazanavir, efavirenz, emtricitabine, maraviroc, ritonavir, and tenofovir.

There are no moderate interactions for this drug.

*Known hypersensitivity to the drug or any ingredient in the formulation.

• Lactation
• Lactic acidosis

• 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

• Chronic hepatitis B

The most common adverse reactions experienced in at least 10% of adult patients with HIV-1 treated with emtricitabine include headache, GI effects (diarrhea, nausea), fatigue, dizziness, depression, insomnia, abnormal dreams, rash, abdominal pain, asthenia, increased cough, and rhinitis. Adverse effects reported in pediatric patients 3 months of age or older receiving emtricitabine in clinical studies have been similar to those in adults, with the exception of a higher frequency of hyperpigmentation.

More Frequent

• Depression
• Gastroenteritis
• Vomiting

Less Frequent

• Anemia
• Bullous dermatitis
• Maculopapular rash
• Peripheral neuropathy
• Urticaria

Rare or Very Rare

• Autoimmune hepatitis
• Graves' disease
• Guillain-barre syndrome
• Lactic acidosis
• Pneumonia
• Polymyositis
• Steatosis of liver

More Frequent

• Acute abdominal pain
• Cough
• Diarrhea
• Dizziness
• Dream disorder
• Fatigue
• General weakness
• Headache disorder
• Nausea
• Pruritus of skin
• Rhinitis
• Skin rash

Less Frequent

• Acute bacterial otitis media
• Arthralgia
• Dyspepsia
• Insomnia
• Myalgia
• Paresthesia

Rare or Very Rare

• Dyschromia

No enhanced messaging available.

Safety and efficacy of emtricitabine have been established for treatment of HIV-1 infection in children 3 months of age and older.

The pharmacokinetics and safety of emtricitabine were evaluated in a dose-finding study in 20 neonates born to HIV-infected mothers. These neonates received zidovudine prophylaxis for 6 weeks. In addition, these neonates received 2 short courses of emtricitabine (3 mg/kg daily for 4 days per course) during the first 12 weeks of life. This dosage was not associated with any safety issues. Systemic exposure (AUC) in infants 0-3 months of age receiving emtricitabine 3 mg/kg daily was similar to that reported in children 3 months to 17 years of age receiving emtricitabine 6 mg/kg daily. All neonates were HIV-1 negative at the end of the study (6 months postpartum); the efficacy of emtricitabine for the prevention or treatment of HIV was not determined.

The Antiretroviral Pregnancy Registry (APR) monitors pregnancy outcomes in women exposed to emtricitabine during pregnancy. Clinicians are encouraged to register patients in the APR by calling 800-258-4263 or visiting https://www.APRegistry.com.

Based on prospective reports to the APR, the overall risk of birth defects among live births with first-trimester exposure to emtricitabine was 2.4%, and 2.3% with second/third trimester exposure, compared to the background rate for major birth defects of 2.7% in the United States reference population of the Metropolitan Atlanta Congenital Defects Program (MACDP). Limitations of using an external comparator (i.e., MACDP) include differences in populations and methodology, and confounding due to the underlying disease. The rate of miscarriage for individual drugs is not reported in the APR.

Additional observational data have not shown an increase in major malformations with emtricitabine exposure in pregnancy.

Based on published data, emtricitabine is distributed into human milk. It is not known whether emtricitabine affects milk production or has effects on the breast-fed infant.

The HHS perinatal HIV transmission guideline provides updated recommendations on infant feeding. The guideline states that patients with HIV should receive evidence-based, patient-centered counseling to support shared decision making about infant feeding. During counseling, patients should be informed that feeding with appropriate formula or pasteurized donor human milk from a milk bank eliminates the risk of postnatal HIV transmission to the infant. Additionally, achieving and maintaining viral suppression with antiretroviral therapy during pregnancy and postpartum reduces the risk of breastfeeding HIV transmission to <1%, but does not completely eliminate the risk. Replacement feeding with formula or banked pasteurized donor milk is recommended when patients with HIV are not on antiretroviral therapy and/or do not have a suppressed viral load during pregnancy (at a minimum throughout the third trimester), as well as at delivery.

The manufacturer makes no specific dosage recommendations for geriatric patients, but recommends cautious dosage selection due to the greater frequency of decreased hepatic, renal, and/or cardiac function, and of concomitant disease and drug therapy.

Experience in those 65 years of age or older is insufficient to determine whether they respond differently to emtricitabine than younger adults. Dosage should be selected with caution because of age-related decreases in hepatic, renal, and/or cardiac function and potential for concomitant disease and drug therapy.