Efavirenz

Efavirenz is an antiviral drug [see Microbiology ( 12.4 )].

• & USAGE Efavirenz in combination with other antiretroviral agents is 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.ICD-10: B20

• • Efavirenz is 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 [ see Warnings and Precautions ( 5.1 ) and Drug Interactions ( 7.1 ) ].contraindicated

DOSAGE & ADMINISTRATION • Efavirenz should be taken orally once daily on an empty stomach, preferably at bedtime. ( 2 ) • Recommended adult dose: 600 mg. ( 2.2 ) • With rifampin, increase efavirenz dose to 800 mg once daily for patients weighing 50 kg or more. ( 2.2 ) • Pediatric dosing is based on weight. ( 2.3 ) 2.1 Hepatic Function Monitor hepatic function prior to and during treatment with efavirenz [ see Warnings and Precautions ( 5.9 ) ]. Efavirenz is not recommended in patients with moderate or severe hepatic impairment (Child Pugh B or C) [ see Warnings and Precautions ( 5.9 ) and Use in Specific Populations ( 8.6 ) ]. 2.2 Adults The recommended dosage of efavirenz is 600 mg orally, once daily, in combination with a protease inhibitor and/or nucleoside analogue reverse transcriptase inhibitors (NRTIs). It is recommended that efavirenz be taken on an empty stomach, preferably at bedtime. The increased efavirenz concentrations observed following administration of efavirenz with food may lead to an increase in frequency of adverse reactions [see Clinical Pharmacology ( 12.3 )]. Dosing at bedtime may improve the tolerability of nervous system symptoms [see Warnings and Precautions ( 5.6 ), Adverse Reactions ( 6.1 ), and Patient Counseling Information ( 17 )]. Efavirenz capsules or tablets should be swallowed intact with liquid. Concomitant Antiretroviral Therapy Efavirenz must be given in combination with other antiretroviral medications [see Indications and Usage ( 1 ), Warnings and Precautions ( 5.3) , Drug Interactions ( 7.1 ), and Clinical Pharmacology ( 12.3 )].

• 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. ( 5.2 ) • 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. ( 5.3 ) •Not recommended with ATRIPLA, which contains efavirenz, emtricitabine, and tenofovir disoproxil fumarate, unless needed for dose adjustment when coadministered with rifampin. ( 5.4 ) • Serious psychiatric symptoms : Immediate medical evaluation is recommended for serious psychiatric symptoms such as severe depression or suicidal ideation. ( 5.5 , 17 ) • Nervous system symptoms (NSS): NSS are frequent and usually begin 1-2 days after initiating therapy and resolve in 2-4 weeks. Dosing at bedtime may improve tolerability. NSS are not predictive of onset of psychiatric symptoms. ( 5.6 , 6.1 , 17 ) • Embryo-Fetal Toxicity : Avoid administration in the first trimester of pregnancy as fetal harm may occur. ( 5.7 , 8.1 ) • Hepatotoxicity : Monitor liver function tests before and during treatment in patients with underlying hepatic disease, including hepatitis B or C coinfection, marked transaminase elevations, or who are taking medications associated with liver toxicity. Among reported cases of hepatic failure, a few occurred in patients with no pre-existing hepatic disease. ( 5.9 , 6.1 , 8.6 ) • Rash : Rash usually begins within 1-2 weeks after initiating therapy and resolves within 4 weeks. Discontinue if severe rash develops.

The most significant adverse reactions observed in patients treated with efavirenz are: •psychiatric symptoms [see Warnings and Precautions ( 5.5 )], •nervous system symptoms [see Warnings and Precautions ( 5.6 )], •rash [see Warnings and Precautions ( 5.8 )]. •hepatotoxicity [see Warnings and Precautions ( 5.9 )] Most common adverse reactions (>5%, moderate-severe) are impaired concentration, abnormal dreams, rash, dizziness, nausea, headache, fatigue, insomnia, and vomiting.( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Macleods Pharmaceutical Ltd at 1-888-943-3210 or 1-855-926-3384 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Because clinical studies are conducted under widely varying conditions, the adverse reaction rates reported cannot be directly compared to rates in other clinical studies and may not reflect the rates observed in clinical practice. Adverse Reactions in Adults.

• Lactation : Breastfeeding not recommended. ( 8.2 ) • Females and Males of Reproductive Potential : Pregnancy testing and contraception are recommended. ( 8.3 ) • Hepatic impairment : Efavirenz is not recommended for patients with moderate or severe hepatic impairment. Use caution in patients with mild hepatic impairment. ( 8.6 ) • Pediatric patients : The incidence of rash was higher than in adults. ( 5.8 , 6.2 , 8.4 ) 8.1 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. Risk Summary There are retrospective case reports of neural tube defects in infants whose mothers were exposed to efavirenz-containing regimens in the first trimester of pregnancy. Prospective pregnancy data from the Antiretroviral Pregnancy Registry are not sufficient to adequately assess this risk. Available data from the Antiretroviral Pregnancy Registry show no difference in the risk of overall major birth defects compared to the background rate for major birth defects of 2.7% in the U.S. reference population of the Metropolitan Atlanta Congenital Defects Program(MACDP).

Metabolism

Absorption Peak efavirenz plasma concentrations of 1.6-9.1 μM were attained by 5 hours following single oral doses of 100 mg to 1600 mg administered to uninfected volunteers. Dose-related increases in C max and AUC were seen for doses up to 1600 mg; the increases were less than proportional suggesting diminished absorption at higher doses.

Some patients accidentally taking 600 mg twice daily have reported increased nervous system symptoms. One patient experienced involuntary muscle contractions. Treatment of overdose with efavirenz should consist of general supportive measures, including monitoring of vital signs and observation of the patient's clinical status. Administration of activated charcoal may be used to aid removal of unabsorbed drug. There is no specific antidote for overdose with efavirenz. Since efavirenz is highly protein bound, dialysis is unlikely to significantly remove the drug from blood.

• Dec 15, 2017ANDAANDA078064Aurobindo Pharma
• Mar 22, 2018NDANDA022142Mylan Labs Ltd
• Apr 27, 2018ANDAANDA078886Hetero Labs Ltd Iii
• Jun 15, 2018ANDAANDA204766Cipla
• Sep 4, 2018ANDAANDA203041Aurobindo Pharma
• Sep 21, 2018ANDAANDA077673Aurobindo Pharma Ltd
• Nov 9, 2018ANDAANDA091215Teva Pharms Usa
• Jun 3, 2019ANDAANDA206894Cipla

1. 1Virologic Failure9568.6%
2. 2Drug Interaction7576.8%
3. 3Drug Resistance7356.6%
4. 4Viral Mutation Identified6746.1%
5. 5Pathogen Resistance6235.6%
6. 6Foetal Exposure During Pregnancy6195.6%
7. 7Depression4594.1%
8. 8Maternal Exposure During Pregnancy4233.8%
9. 9Treatment Failure4233.8%
10. 10Anaemia4173.8%
11. 11Pyrexia3823.4%
12. 12Immune Reconstitution Inflammatory Syndrome3793.4%
13. 13Vomiting3513.2%
14. 14Death3393.1%
15. 15Diarrhoea3042.7%

The 10 most recently updated of 486 ClinicalTrials.gov registrations naming Efavirenz as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

• A Study to Provide Continued Access to Study Drug to Children and Adolescents Who Have Completed Clinical Studies Involving Gilead HIV Treatments
  Recruiting · Phase 4 · Interventional · 350 enrolled · Gilead Sciences
  NCT06337032updated 2026-06-10
• Comparative Trial Between Ainuovirine(ANV)/Lamivudine(3TC)/Tenofovir(TDF) and Efavirenz(EFV)/Lamivudine/Tenofovir Regimens
  Not yet recruiting · Phase 4 · Interventional · 60 enrolled · Shanghai Public Health Clinical Center
  NCT07631897updated 2026-06-08
• Biktarvy in Treatment-Naïve Late Presenters With HIV-1 Infection
  Completed · Phase 4 · Interventional · 202 enrolled · Peking Union Medical College Hospital
  NCT04296695updated 2026-06-05
• Effects of Efavirenz on the Pharmacokinetics of Suzetrigine in Healthy Participants
  Recruiting · Phase 1 · Interventional · 18 enrolled · Vertex Pharmaceuticals Incorporated
  NCT07570069updated 2026-06-02
• Interaction of CYP2B6 Genotype and Efavirenz With Methadone and Tizanidine PK
  Recruiting · Early phase 1 · Interventional · 60 enrolled · Indiana University
  NCT05789173updated 2026-05-29
• Drug-Drug Interactions of JMKX003142 in Healthy Participants
  Not yet recruiting · Phase 1 · Interventional · 112 enrolled · Jemincare
  NCT07565441updated 2026-05-04
• A Single-center, Randomized, Open-label, Parallel-design Clinical Study to Evaluate the Pharmacokinetic Effects of Itraconazole, Fluconazole or Efavirenz on a Single Dose of Clifutinib in Healthy Participants
  Not yet recruiting · Phase 1 · Interventional · 80 enrolled · Sunshine Lake Pharma Co., Ltd.
  NCT07341672updated 2026-04-27
• Study of Cobicistat-Boosted Atazanavir (ATV/co), Cobicistat-Boosted Darunavir (DRV/co) and Emtricitabine/Tenofovir Alafenamide (F/TAF) in Children With HIV
  Active not recruiting · Phase 2 · Phase 3 · Interventional · 133 enrolled · Gilead Sciences
  NCT02016924updated 2026-04-21
• Impact of Immediate Versus South African Recommendations Guided ART Initiation on HIV Incidence
  Completed · Interventional · 28,153 enrolled · ANRS, Emerging Infectious Diseases
  NCT01509508updated 2026-04-15
• Antiretroviral Treatment Taken 4 Days Per Week Versus Continuous Therapy 7/7 Days Per Week in HIV-1 Infected Patients
  Completed · Phase 3 · Interventional · 640 enrolled · ANRS, Emerging Infectious Diseases
  NCT03256422updated 2026-04-13

CPIC-curated drug–gene pairs for Efavirenz. Levels describe the strength of curated evidence and guideline status — never a recommendation to test or to adjust therapy.

• CYP2B6CPIC AClinPGx 1AFDA label: Informative PGx
  CYP2B6 and efavirenz

Frequently asked questions

How does Efavirenz work?

Efavirenz is an antiviral drug [see Microbiology ( 12.4 )].

What is Efavirenz used for?

According to FDA labeling, Efavirenz carries indications including: & USAGE Efavirenz in combination with other antiretroviral agents is 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.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.

What class of drug is Efavirenz?

Efavirenz is classified as Non-nucleoside reverse transcriptase inhibitors, Human Immunodeficiency Virus 1 Non-Nucleoside Analog Reverse Transcriptase Inhibitor, Cytochrome P450 2B6 Inducers, Cytochrome P450 2C19 Inhibitors, Cytochrome P450 2C9 Inhibitors, Cytochrome P450 3A Inducers, Cytochrome P450 3A4 Inhibitors, Non-Nucleoside Reverse Transcriptase Inhibitors, Decreased Reverse Transcription to DNA.

What are the brand names for Efavirenz?

Efavirenz is marketed under brand names including Atripla, Symfi.

What are the contraindications for Efavirenz?

Efavirenz labeling lists contraindications including: • Efavirenz is 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 [ see Warnings and Precautions ( 5.1 ) and Drug Interactions ( 7.1 ) ].. Always consult the full prescribing information and a clinician.