Efavirenz / Emtricitabine / Tenofovir Dosage

Medically reviewed by Drugs.com. Last updated on Aug 14, 2023.

Usual Adult Dose for HIV Infection

1 tablet orally once a day

Use: As a complete regimen or in combination with other antiretroviral agents for the treatment of HIV-1 infection

Usual Adult Dose for Nonoccupational Exposure

US CDC Recommendations: 1 tablet orally once a day
Duration of therapy: 28 days

Comments:

• Only with expert consultation, an alternative regimen for HIV nonoccupational postexposure prophylaxis (nPEP)
• Efavirenz is contraindicated as nPEP in pregnant women; it should be avoided in nPEP regimens during the first trimester and should not be used for women of childbearing potential who might become pregnant during antiretroviral prophylaxis.
• Prophylaxis should be started as soon as possible, within 72 hours of exposure.
• Current guidelines should be consulted for additional information.

Usual Adult Dose for Occupational Exposure

US Public Health Service working group recommendations: 1 tablet orally once a day
Duration of therapy: 28 days, if tolerated

Comments:

• Only with expert consultation, an alternative regimen for use as HIV postexposure prophylaxis
• Prophylaxis should be started as soon as possible, preferably within hours after exposure.
• The optimal duration of prophylaxis is unknown and may differ based on institution protocol.
• Current guidelines should be consulted for additional information.

Usual Pediatric Dose for HIV Infection

At least 40 kg: 1 tablet orally once a day

Use: As a complete regimen or in combination with other antiretroviral agents for the treatment of HIV-1 infection

Renal Dose Adjustments

Moderate or severe renal dysfunction (estimated CrCl less than 50 mL/min): Not recommended.

Liver Dose Adjustments

Mild liver dysfunction (Child-Pugh A): No adjustment recommended; caution recommended.
Moderate to severe liver dysfunction (Child-Pugh B or C): Not recommended.

Dose Adjustments

Concomitant rifampin:

• Patients weighing at least 50 kg: After administration of this drug (1 tablet orally once a day), an additional 200 mg/day of efavirenz is recommended.

Precautions

US BOXED WARNING:

• POSTTREATMENT ACUTE EXACERBATION OF HEPATITIS B: Severe acute exacerbations of HBV reported in patients coinfected with HIV-1 and HBV after stopping products containing emtricitabine and/or tenofovir disoproxil fumarate. Hepatic function of HIV-1/HBV-coinfected patients should be closely monitored with clinical and laboratory follow-up for at least several months after stopping this drug. If appropriate, initiation of antihepatitis B therapy may be necessary.

CONTRAINDICATIONS:

• Previously demonstrated clinically significant hypersensitivity (e.g., Stevens-Johnson syndrome, erythema multiforme, toxic skin eruptions) to efavirenz
• Coadministration with voriconazole or elbasvir-grazoprevir

Safety and efficacy have not been established in pediatric patients weighing less than 40 kg; this drug is not recommended for use in these patients.

Consult WARNINGS section for additional precautions.

Dialysis

Data not available

Other Comments

Administration advice:

• Test patients for HBV infection before or when starting this drug.
• In all patients, assess serum creatinine, estimated CrCl, urine glucose, and urine protein before starting and during therapy as clinically appropriate; in patients with chronic kidney disease, also assess serum phosphorus.
• Monitor hepatic function before and during therapy.
• Perform pregnancy testing before starting this drug in adolescents and adults of childbearing potential.
• Administer on an empty stomach.
• Dosing at bedtime may improve tolerability of nervous system symptoms.

Storage requirements:

• Store in the original bottle; keep bottle tightly closed.
• Store at 25C (77F); excursions permitted to 15C to 30C (59F to 86F).

General:

• Each 3-drug fixed-dose combination tablet contains efavirenz 600 mg, emtricitabine 200 mg, and tenofovir disoproxil fumarate 300 mg.

Monitoring:

• General: Pregnancy testing in patients of childbearing potential (before starting therapy)
• Hepatic: Liver enzymes/hepatic function (before and during therapy); for chronic HBV in all patients (before therapy); hepatic function of HIV-1/HBV-coinfected patients with clinical and laboratory follow-up (for at least several months after stopping therapy)
• Infections/Infestations: For chronic HBV infection in all patients (before or when starting therapy)
• Metabolic: Serum phosphorus in patients with chronic kidney disease (before starting and as clinically appropriate during therapy)
• Musculoskeletal: Bone mineral density in patients with history of pathologic bone fracture or other risk factors for osteoporosis or bone loss
• Renal: Serum creatinine, estimated CrCl, urine glucose, and urine protein in all patients (before starting and as clinically appropriate during therapy)

Patient advice:

• Read the US FDA-approved patient labeling (Patient Information).
• If you also have HBV, do not stop this drug without consulting healthcare provider.
• Contact physician without delay if rash occurs.
• Watch for early signs of liver inflammation or failure (e.g., fatigue, weakness, lack of appetite, nausea and vomiting) as well as later signs (e.g., jaundice, confusion, abdominal swelling, discolored feces); consult healthcare professional at once if such symptoms occur.
• Seek immediate medical evaluation if severe psychiatric side effects occur.
• Avoid potentially hazardous tasks (e.g., driving, operating machinery) if CNS symptoms (e.g., dizziness, impaired concentration, drowsiness) occur.
• Avoid taking this drug with concurrent/recent use of nephrotoxic agents.
• If of childbearing potential, avoid pregnancy and inform healthcare provider if you become pregnant or plan to become pregnant while using this drug; always use a reliable form of barrier contraception with other methods of contraception (including oral or other hormonal contraception) during therapy and for 12 weeks after stopping this drug.
• Notify healthcare provider at once of any symptoms of infection.
• Take this drug on a regular dosing schedule to avoid missing doses.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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