Efavirenz Tablets Dosage & Rx Info

Efavirenz Tablets Generic Name & Formulations

Legal Class

General Description

Efavirenz 600mg.

Pharmacological Class

Non-nucleoside reverse transcriptase inhibitor.

How Supplied

Contact supplier

Manufacturer

Various generic manufacturers

Mechanism of Action

Efavirenz is a non-nucleoside reverse transcriptase inhibitor (NNRTI) that is mediated predominantly by noncompetitive inhibition of HIV-1 reverse transcriptase.

Efavirenz Tablets Indications

Indications

HIV-1 infection, in combination with other antiretroviral agents.

Efavirenz Tablets Dosage and Administration

Adults and Children

Swallow whole; do not break tabs. If unable to swallow tabs or caps: may sprinkle capsule content and mix in 1–2tsps of soft food (eg, applesauce, grape jelly, yogurt) or 2tsps of room temperature infant formula; administer within 30mins of mixing. Give once daily on an empty stomach, preferably at bedtime. Consider pretreating with antihistamine (for children) or steroid to minimize rash. <3mos or <3.5kg: not recommended. ≥3mos (3.5kg to <5kg): 100mg; (5kg to <7.5kg): 150mg; (7.5kg to <15kg): 200mg; (15kg to <20kg): 250mg; (20kg to <25kg): 300mg; (25kg to <32.5kg): 350mg; (32.5kg to <40kg): 400mg; (≥40kg) and adults: 600mg. Concomitant voriconazole: increase voriconazole maintenance dose to 400mg every 12hrs and decrease efavirenz dose to 300mg once daily using capsule form. Concomitant rifampin (patient ≥50kg): increase efavirenz dose to 800mg once daily.

Administration

Swallow whole; do not break tabs. If unable to swallow tabs or caps: may sprinkle capsule content and mix in 1–2tsps of soft food (eg, applesauce, grape jelly, yogurt) or 2tsps of room temperature infant formula; administer within 30mins of mixing. Do not consume additional food for 2hrs after dose. Take on an empty stomach, preferably at bedtime. Missed dose: take missed dose right away unless it is almost time for the next dose; do not double the next dose.

Nursing Considerations

Swallow whole; do not break tabs. If unable to swallow tabs or caps: may sprinkle capsule content and mix in 1–2tsps of soft food (eg, applesauce, grape jelly, yogurt) or 2tsps of room temperature infant formula; administer within 30mins of mixing. Do not consume additional food for 2hrs after dose. Take on an empty stomach, preferably at bedtime. Missed dose: take missed dose right away unless it is almost time for the next dose; do not double the next dose.

Efavirenz Tablets Contraindications

Contraindications

Concomitant elbasvir/grazoprevir.

Efavirenz Tablets Boxed Warnings

Not Applicable

Efavirenz Tablets Warnings/Precautions

Warnings/Precautions

CNS or psychiatric disturbances. QTc prolongation. Underlying hepatic disease (including hepatitis B or C coinfection). Hepatic impairment: moderate or severe: not recommended; mild: monitor. Monitor liver function before and during therapy in all patients; consider discontinuing in persistent serum transaminase elevations to >5×ULN and discontinue if elevation is accompanied by signs/symptoms of hepatitis or hepatic decompensation. History of seizures. Monitor cholesterol and triglycerides before starting and periodically thereafter. Discontinue if severe rash (w. blistering, desquamation, mucosal involvement, or fever) occurs. Obtain (–) pregnancy test before starting; use adequate (barrier + hormonal) contraception during and for 12 weeks after discontinuation. Elderly. Embryo-fetal toxicity. Pregnancy: avoid (esp. during 1^st trimester). Nursing mothers: not recommended.

Efavirenz Tablets Pharmacokinetics

Distribution

Plasma protein bound: ~99.5–99.75% (mostly albumin).

Metabolism

Hepatic (CYP3A, CYP2B6).

Elimination

Fecal (16–61%), renal (14–34%).

Half-life: 52–76 hours (after single doses); 40–55 hours (after multiple doses).

Efavirenz Tablets Interactions

Interactions

Avoid concomitant other efavirenz-containing products (eg, Atripla unless needed for dose adjustment with rifampin), atazanavir (treatment-experienced), boceprevir, posaconazole, praziquantel, simeprevir, atovaquone/proguanil, pibrentasvir/glecaprevir, velpatasvir/sofosbuvir/voxilaprevir, alcohol, psychoactive, other NNRTIs or hepatotoxic drugs. Caution with drugs metabolized by, or that affect activity of, CYP2B6 or CYP3A4. Efavirenz levels decreased by carbamazepine, phenytoin, phenobarbital, rifampin (adjust dose). May decrease levels of indinavir, amprenavir, atazanavir, saquinavir, anticonvulsants, clarithromycin, calcium channel blockers (eg, diltiazem, felodipine, nicardipine, nifedipine, verapamil), itraconazole, ketoconazole, lopinavir (adjust dose: see full labeling), maraviroc, bupropion, methadone, rifabutin (increase dose; see full labeling), sertraline, simvastatin, atorvastatin, pravastatin, hormonal contraceptives (eg, norgestimate, etonogestrel), immunosuppressants (eg, cyclosporine, sirolimus, tacrolimus), artemether/lumefantrine. May affect or be affected by voriconazole (adjust dose). Levels of both drugs increased with ritonavir (monitor liver function and for adverse events). Closely monitor warfarin, anticonvulsants (esp. phenytoin, phenobarbital, carbamazepine), others. Consider alternatives when concomitant drugs with a risk of QT prolongation (eg, clarithromycin, artemether/lumefantrine). May cause false (+) cannabis screening test results.

Efavirenz Tablets Adverse Reactions

Adverse Reactions

CNS effects (eg, dizziness, headache, insomnia, impaired concentration, somnolence, abnormal dreams), psychiatric effects (eg, severe depression, suicidal ideation/attempt, aggression, paranoia, mania, delusions, psychosis), rash (may be severe; eg, Stevens-Johnson, erythema multiforme), nausea, vomiting, fatigue; immune reconstitution syndrome, fat redistribution, hepatotoxicity, dyslipidemia, late-onset neurotoxicity (eg, ataxia, encephalopathy).

Efavirenz Tablets Clinical Trials

See Literature

Efavirenz Tablets Note

Notes

Formerly known under the brand name Sustiva. Register pregnant patients exposed to efavirenz by calling (800) 258-4263.

Efavirenz Tablets Patient Counseling