Efavirenz

1 INDICATIONS AND USAGE Efavirenz capsules 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 is 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. ( 1 )

2 DOSAGE AND ADMINISTRATION Efavirenz capsules should be taken orally once daily on an empty stomach, preferably at bedtime. ( 2 ) Recommended adult dose: 600 mg. ( 2.2 ) 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. (2.2) With rifampin, increase efavirenz capsules 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 capsules [see Warnings and Precautions (5.9) ] . Efavirenz capsules are 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 capsules 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 capsules be taken on an empty stomach, preferably at bedtime. The increased efavirenz concentrations observed following administration of efavirenz capsules 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 should be swallowed intact with liquid. For patients who cannot swallow capsules, the capsule sprinkle method of administration is recommended [see Dosage and Administration (2.4) ]. Concomitant Antiretroviral Therapy Efavirenz capsules 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) ] . Dosage Adjustment If efavirenz capsules are coadministered with voriconazole, the voriconazole maintenance dose should be increased to 400 mg every 12 hours and the efavirenz dose should be decreased to 300 mg once daily using the capsule formulation (one 200 mg and two 50 mg capsules or six 50 mg capsules). If efavirenz capsules are coadministered with rifampin to patients weighing 50 kg or more, an increase in the dose of efavirenz capsules to 800 mg once daily is recommended [see Drug Interactions (7.1, Table 5 ) and Clinical Pharmacology (12.3, Table 8) ]. 2.3 Pediatric Patients It is recommended that efavirenz capsules be taken on an empty stomach, preferably at bedtime. Table 1 describes the recommended dose of efavirenz capsules for pediatric patients 3 months of age or older and weighing between 3.5 kg and 40 kg [see Clinical Pharmacology (12.3) ] . The recommended dosage of efavirenz capsules for pediatric patients weighing 40 kg or greater is 600 mg once daily. For pediatric patients who cannot swallow capsules, the capsule contents can be administered with a small amount of food or infant formula using the capsule sprinkle method of administration [see Dosage and Administration (2.4) ]. Table 1: Efavirenz Capsules Dosing in Pediatric Patients Patient Body Weight Efavirenz Capsules Daily Dose Number of Capsules a and Strength to Administer 3.5 kg to less than 5 kg 100 mg two 50 mg capsules 5 kg to less than 7.5 kg 150 mg three 50 mg capsules 7.5 kg to less than 15 kg 200 mg one 200 mg capsule 15 kg to less than 20 kg 250 mg one 200 mg + one 50 mg capsule 20 kg to less than 25 kg 300 mg one 200 mg + two 50 mg capsules 25 kg to less than 32.5 kg 350 mg one 200 mg + three 50 mg capsules 32.5 kg to less than 40 kg 400 mg two 200 mg capsules at least 40 kg 600 mg three 200 mg capsules a Capsules can be administered intact or as sprinkles [see Dosage and Administration (2.4) ]. 2.4 Capsule Sprinkle Method of Administration For pediatric patients at least 3 months old and weighing at least 3.5 kg and adults who…

5 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. ( 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 to 2 days after initiating therapy and resolve in 2 to 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 to 2 weeks after initiating therapy and resolves within 4 weeks. Discontinue if severe rash develops. ( 5.8 , 6.1 , 17 ) Convulsions: Use caution in patients with a history of seizures. ( 5.10 ) Lipids: Total cholesterol and triglyceride elevations. Monitor before therapy and periodically thereafter. ( 5.11 ) Immune reconstitution syndrome: May necessitate further evaluation and treatment. ( 5.12 ) Redistribution/accumulation of body fat: Observed in patients receiving antiretroviral therapy. ( 5.13 , 17 ) 5.1 Drug Interactions Efavirenz plasma concentrations may be altered by substrates, inhibitors, or inducers of CYP3A. Likewise, efavirenz may alter plasma concentrations of drugs metabolized by CYP3A or CYP2B6. The most prominent effect of efavirenz at steady state is induction of CYP3A and CYP2B6 [see Dosage and Administration (2.2) and Drug Interactions (7.1) ]. 5.2 QTc Prolongation QTc prolongation has been observed with the use of efavirenz [see Drug Interactions (7.3 , 7.4 ) and Clinical Pharmacology (12.2) ] . Consider alternatives to efavirenz when coadministered with a drug with a known risk of Torsade de Pointes or when administered to patients at higher risk of Torsade de Pointes. 5.3 Resistance Efavirenz must not be used as a single agent to treat HIV-1 infection or added on as a sole agent to a failing regimen. Resistant virus emerges rapidly when efavirenz is administered as monotherapy. The choice of new antiretroviral agents to be used in combination with efavirenz should take into consideration the potential for viral cross-resistance. 5.4 Coadministration with Related Products Coadministration of efavirenz with ATRIPLA (efavirenz 600 mg/emtricitabine 200 mg/tenofovir disoproxil fumarate 300 mg) is not recommended unless needed for dose adjustment (e.g., with rifampin), since efavirenz is one of its active ingredients. 5.5 Psychiatric Symptoms Serious psychiatric adverse experiences have been reported in patients treated with efavirenz. In controlled trials of 1008 patients treated with regimens containing efavirenz for a mean of 2.1 years and 635 patients treated with control regimens for a mean of 1.5 years, the frequency (regardless of causality) of specific serious psychiatric events among patients who received efavirenz or control regimens, respectively, were severe depression (2.4%, 0.9%), suicidal ideation (0.7%, 0.3%), nonfatal suicide attempts (0.5%, 0), aggressive behavior (0.4%, 0.5%), paranoid reactions (0.4%, 0.3%), and…

4 CONTRAINDICATIONS Efavirenz capsules 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 [see Warnings and Precautions (5.1) and Drug Interactions (7.1) ]. Patients with previously demonstrated hypersensitivity (e.g., Stevens-Johnson syndrome, erythema multiforme, or toxic skin eruptions) to any of the components of this product. (4) Coadministration of efavirenz with elbasvir/grazoprevir.

7 DRUG INTERACTIONS Coadministration of efavirenz can alter the concentrations of other drugs and other drugs may alter the concentrations of efavirenz. The potential for drug-drug interactions should be considered before and during therapy. ( 7 ) 7.1 Potential for Efavirenz to Affect other Drugs Efavirenz has been shown in vivo to induce CYP3A and CYP2B6. Other compounds that are substrates of CYP3A or CYP2B6 may have decreased plasma concentrations when coadministered with efavirenz. 7.2 Potential for Other Drugs to Affect Efavirenz Drugs that induce CYP3A activity (e.g., phenobarbital, rifampin, rifabutin) would be expected to increase the clearance of efavirenz resulting in lowered plasma concentrations [see Dosage and Administration (2.2) ]. 7.3 QT Prolonging Drugs There is limited information available on the potential for a pharmacodynamic interaction between efavirenz and drugs that prolong the QTc interval. QTc prolongation has been observed with the use of efavirenz [see Clinical Pharmacology (12.2) ] . Consider alternatives to efavirenz when coadministered with a drug with a known risk of Torsade de Pointes. 7.4 Established and Other Potentially Significant Drug Interactions Drug interactions with efavirenz are summarized in Table 5. For pharmacokinetics data, [see Clinical Pharmacology (12.3) ] Tables 7 and 8. This table includes potentially significant interactions, but is not all inclusive. Table 5: Established and Other Potentially Significant Drug Interactions: Alteration in Dose or Regimen May Be Recommended Based on Drug Interaction Studies or Predicted Interaction * The interaction between efavirenz and the drug was evaluated in a clinical study. All other drug interactions shown are predicted. This table is not all-inclusive. Concomitant Drug Class: Drug Name Effect Clinical Comment HIV antiviral agents Protease inhibitor: Fosamprenavir Calcium ↓ amprenavir Fosamprenavir (unboosted): Appropriate doses of the combinations with respect to safety and efficacy have not been established. Fosamprenavir/ritonavir: An additional 100 mg/day (300 mg total) of ritonavir is recommended when efavirenz is administered with fosamprenavir/ritonavir once daily. No change in the ritonavir dose is required when efavirenz is administered with fosamprenavir plus ritonavir twice daily. Protease inhibitor: Atazanavir ↓ atazanavir* Treatment-naive patients: When coadministered with efavirenz, the recommended dose of atazanavir is 400 mg with ritonavir 100 mg (together once daily with food) and efavirenz 600 mg (once daily on an empty stomach, preferably at bedtime). Treatment-experienced patients: Coadministration of efavirenz and atazanavir is not recommended. Protease inhibitor: Indinavir ↓ indinavir* The optimal dose of indinavir, when given in combination with efavirenz, is not known. Increasing the indinavir dose to 1000 mg every 8 hours does not compensate for the increased indinavir metabolism due to efavirenz. Protease inhibitor: Lopinavir/ritonavir ↓ lopinavir* Lopinavir/ritonavir once daily dosing is not recommended when coadministered with efavirenz. The dose of lopinavir/ritonavir must be increased when coadministered with efavirenz. See the lopinavir/ritonavir prescribing information for dose adjustments of lopinavir/ritonavir when coadministered with efavirenz in adult and pediatric patients. Protease inhibitor: Ritonavir ↑ ritonavir* ↑ efavirenz* Monitor for elevation of liver enzymes and for adverse clinical experiences (e.g., dizziness, nausea, paresthesia) when efavirenz is coadministered with ritonavir. Protease inhibitor: Saquinavir ↓ saquinavir* Appropriate doses of the combination of efavirenz and saquinavir/ritonavir with respect to safety and efficacy have not been established. NNRTI: Other NNRTIs ↑ or ↓ efavirenz and/or NNRTI Combining two NNRTIs has not been shown to be beneficial. Efavirenz should not be coadministered with other NNRTIs. CCR5 co-receptor antagonist: Maraviroc ↓ maraviroc* Refer to the fu…

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). Although a causal relationship has not been established between exposure to efavirenz in the first trimester and neural tube defects, similar malformations have been observed in studies conducted in monkeys at doses similar to the human dose. In addition, fetal and embryonic toxicities occurred in rats, at a dose ten times less than the human exposure at recommended clinical dose. Because of the potential risk of neural tube defects, efavirenz should not be used in the first trimester of pregnancy. Advise pregnant women of the potential risk to a fetus. Data Human Data There are retrospective postmarketing reports of findings consistent with neural tube defects, including meningomyelocele, all in infants of mothers exposed to efavirenz-containing regimens in the first trimester. Based on prospective reports from the Antiretroviral Pregnancy Registry (APR) of approximately 1000 live births following exposure to efavirenz-containing regimens (including over 800 live births exposed in the first trimester), there was no difference between efavirenz and overall birth defects compared with the background birth defect rate of 2.7% in the U.S. reference population of the Metropolitan Atlanta Congenital Defects Program. As of the interim APR report issued December 2014, the prevalence of birth defects following first-trimester exposure was 2.3% (95% CI: 1.4% to 3.6%). One of these prospectively reported defects with first-trimester exposure was a neural tube defect. A single case of anophthalmia with first-trimester exposure to efavirenz has also been prospectively reported. This case also included severe oblique facial clefts and amniotic banding, which have a known association with anophthalmia. Animal Data Effects of efavirenz on embryo-fetal development have been studied in three nonclinical species (cynomolgus monkeys, rats, and rabbits). In monkeys, efavirenz 60 mg/kg/day was administered to pregnant females throughout pregnancy (gestation days 20 through 150). The maternal systemic drug exposures (AUC) were 1.3 times the exposure in humans at the recommended clinical dose (600 mg/day), with fetal umbilical venous drug concentrations approximately 0.7 times the maternal values. Three of 20 fetuses/infants had one or more malformations; there were no malformed fetuses or infants from placebo-treated mothers. The malformations that occurred in these three monkey fetuses included anencephaly and unilateral anophthalmia in one fetus, microphthalmia in a second, and cleft palate in the third. There was no NOAEL (no observable adverse effect level) established for this study because only one dosage was evaluated. In rats, efavirenz was administered either during organogenesis (gestation days 7 to 18) or from gestation day 7 through lactation day 21 at 50, 100, or 200 mg/kg/day. Administration of 200 mg/kg/day in rats was associated with increase in the incidence of early resorptions; and doses 100 mg/kg/day and greater were associated with early neonatal mortality. The AUC at the NOAEL (50 mg/kg/day) in this rat study was 0.1 times that in humans at the recommended clinical dose. Drug concent…

8.3 Females and Males of Reproductive Potential Because of potential teratogenic effects, pregnancy should be avoided in women receiving efavirenz [see Use in Specific Populations (8.1) ]. Pregnancy Testing Females of reproductive potential should undergo pregnancy testing before initiation of efavirenz. Contraception Females of reproductive potential should use effective contraception during treatment with efavirenz and for 12 weeks after discontinuing efavirenz due to the long half-life of efavirenz. Barrier contraception should always be used in combination with other methods of contraception. Hormonal methods that contain progesterone may have decreased effectiveness [see Drug Interactions (7.1) ] .

6 ADVERSE REACTIONS 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 Aurobindo Pharma USA, Inc. at 1-866-850-2876 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 The most common (>5% in either efavirenz treatment group) adverse reactions of at least moderate severity among patients in Study 006 treated with efavirenz in combination with zidovudine/lamivudine or indinavir were rash, dizziness, nausea, headache, fatigue, insomnia, and vomiting. Selected clinical adverse reactions of moderate or severe intensity observed in ≥2% of efavirenz-treated patients in two controlled clinical trials are presented in Table 2. Table 2: Selected Treatment-Emergent a Adverse Reactions of Moderate or Severe Intensity Reported in ≥2% of Efavirenz-Treated Patients in Studies 006 and ACTG 364 Study 006 LAM-, NNRTI-, and Protease Inhibitor-Naive Patients Study ACTG 364 NRTI-experienced, NNRTI-, and Protease Inhibitor-Naive Patients Adverse Reactions Efavirenz b + ZDV/LAM (n=412) 180 weeks c Efavirenz b + Indinavir (n=415) 102 weeks c Indinavir + ZDV/LAM (n=401) 76 weeks c Efavirenz b + Nelfinavir + NRTIs (n=64) 71.1 weeks c Efavirenz b + NRTIs (n=65) 70.9 weeks c Nelfinavir + NRTIs (n=66) 62.7 weeks c Body as a Whole Fatigue 8% 5% 9% 0 2% 3% Pain 1% 2% 8% 13% 6% 17% Central and Peripheral Nervous System Dizziness 9% 9% 2% 2% 6% 6% Headache 8% 5% 3% 5% 2% 3% Insomnia 7% 7% 2% 0 0 2% Concentration impaired 5% 3% <1% 0 0 0 Abnormal dreams 3% 1% 0 - - - Somnolence 2% 2% <1% 0 0 0 Anorexia 1% <1% <1% 0 2% 2% Gastrointestinal Nausea 10% 6% 24% 3% 2% 2% Vomiting 6% 3% 14% - - - Diarrhea 3% 5% 6% 14% 3% 9% Dyspepsia 4% 4% 6% 0 0 2% Abdominal pain 2% 2% 5% 3% 3% 3% Psychiatric Anxiety 2% 4% <1% - - - Depression 5% 4% <1% 3% 0 5% Nervousness 2% 2% 0 2% 0 2% Skin & Appendages Rash d 11% 16% 5% 9% 5% 9% Pruritus <1% 1% 1% 9% 5% 9% a Includes adverse events at least possibly related to study drug or of unknown relationship for Study 006. Includes all adverse events regardless of relationship to study drug for Study ACTG 364. b Efavirenz provided as 600 mg once daily. c Median duration of treatment. d Includes erythema multiforme, rash, rash erythematous, rash follicular, rash maculopapular, rash petechial, rash pustular, and urticaria for Study 006 and macules, papules, rash, erythema, redness, inflammation, allergic rash, urticaria, welts, hives, itchy, and pruritus for ACTG 364. — = Not Specified. ZDV = zidovudine, LAM = lamivudine. Pancreatitis has been reported, although a causal relationship with efavirenz has not been established. Asymptomatic increases in serum amylase levels were observed in a significantly higher number of patients treated with efavirenz 600 mg than in control patients (see Laboratory Abnormalities ). Nervous System Symptoms For 1008 patients treated with regimens containing efavirenz and 635 patients treated with a control regimen in controlled trials, Table 3 lists the frequency of symptoms of different degrees of severity and gives the discontinuation rates for one or more of the following nervous system symptoms: dizziness, insomnia, impaired concentration, somnolence, abnormal dreaming, euphoria, confusion, agitation, amnesia, hallucinations, stupor, abnormal thinking, and de…