Efavirenz

What it is and how it works

Mechanism of Action Efavirenz is an antiviral drug .

Mechanism class: Non-Nucleoside Reverse Transcriptase Inhibitors · Cytochrome P450 3A Inducers · Cytochrome P450 2B6 Inducers

Indications

Efavirenz tablets in combination with other antiretroviral agents are indicated for the treatment of human immunodeficiency virus type 1 (HIV-1) infection in adults and in pediatric patients at least 3 months old and weighing at least 3.5 kg. Efavirenz tablets are a non-nucleoside reverse transcriptase inhibitor indicated in combination with other antiretroviral agents for the treatment of human immunodeficiency virus type 1 infection in adults and in pediatric patients at least 3 months old and weighing at least 3.5 kg.

Dosage and administration (summary)

Efavirenz tablets should be taken orally once daily on an empty stomach, preferably at bedtime. Recommended adult dose: 600 mg. With voriconazole, increase voriconazole maintenance dose to 400 mg every 12 hours and decrease efavirenz dose to 300 mg once daily using the capsule formulation. With rifampin, increase efavirenz dose to 800 mg once daily for patients weighing 50 kg or more. Pediatric dosing is based on weight. Hepatic Function Monitor hepatic function prior to and during treatment with efavirenz tablets . Efavirenz tablets are not recommended in patients with moderate or severe hepatic impairment (Child Pugh B or C) .

Contraindications

Efavirenz tablets are contraindicated in patients with previously demonstrated clinically significant hypersensitivity (e.g., Stevens-Johnson syndrome, erythema multiforme, or toxic skin eruptions) to any of the components of this product. Coadministration of efavirenz with elbasvir and grazoprevir is contraindicated . Patients with previously demonstrated hypersensitivity (e.g., Stevens-Johnson syndrome, erythema multiforme, or toxic skin eruptions) to any of the components of this product.

Warnings and precautions

QTc prolongation: Consider alternatives to efavirenz in patients taking other medications with a known risk of Torsade de Pointes or in patients at higher risk of Torsade de Pointes. Do not use as a single agent or add on as a sole agent to a failing regimen. Consider potential for cross-resistance when choosing other agents. Not recommended with ATRIPLA, which contains efavirenz, emtricitabine, and tenofovir disoproxil fumarate, unless needed for dose adjustment when coadministered with rifampin.

Pregnancy

Pregnancy Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to efavirenz during pregnancy. Physicians are encouraged to register patients by calling the Antiretroviral Pregnancy Registry at 1-800-258-4263.

Storage and supply

Tablets Efavirenz tablets USP are available as follows: Efavirenz tablets USP 600 mg are yellow colored oval biconvex film-coated tablets debossed ‘D’ on one side and ‘37’ on other side. Bottles of 30 NDC 65862-049-30 30 Unit-dose Tablets NDC 65862-049-10 Storage Efavirenz tablets should be stored at 20° to 25°C (68° to 77°F).

Source: Efavirenz (Efavirenz) — US FDA prescribing information, 2023-12-29, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.