HIV-1 infection, in combination with other antiretroviral agents.
Adults and Children's Dose:
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. <3months: not recommended. ≥3months (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 12 hours and decrease efavirenz dose to 300mg once daily using capsule form. Concomitant rifampin (patient >50kg): increase efavirenz dose to 800mg once daily.
Concomitant bepridil, cisapride, ergots, midazolam, triazolam, pimozide, St. John's wort.
CNS or psychiatric disturbances. Hepatic impairment: moderate or severe: not recommended; mild: use caution. Monitor liver function before and during therapy in patients with underlying diseases (eg, hepatitis B or C coinfection, marked transaminase elevations, being treated with other hepatotoxic drugs). 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. Pregnancy (Cat.D; avoid esp. during 1st trimester). Nursing mothers: not recommended.
See Contraindications. Avoid concomitant other efavirenz-containing products (eg, Atripla unless needed for dose adjustment wth rifampin), atazanavir (treatment-experienced), posaconazole, alcohol, psychoactive and/or other hepatotoxic drugs. Caution with drugs metabolized by, or that affect activity of, CYP2C9, CYP2C19, CYP3A4. Efavirenz levels decreased by carbamazepine, phenytoin, phenobarbital, rifampin (adjust dose), rifabutin. May decrease levels of indinavir, amprenavir, atazanavir, anticonvulsants, clarithromycin, calcium channel blockers (eg, diltiazem, felodipine, nicardipine, nifedipine, verapamil), itraconazole, ketoconazole, lopinavir (adjust dose: see literature), maraviroc, raltegravir, bupropion, methadone, rifabutin (increase dose: see literature), sertraline, simvastatin, atorvastatin, pravastatin, progestins (eg, norelgestromin, levonorgestrel), etonogestrel, immunosuppressants (eg, cyclosporine, sirolimus, tacrolimus). Efavirenz increases nelfinavir plasma levels. May affect or be affected by voriconazole (adjust dose). Levels of both drugs increased with ritonavir (monitor liver function and for adverse events). Levels of both drugs are decreased with telaprevir, or saquinavir (do not use as sole protease inhibitor). Closely monitor warfarin, anticonvulsants (esp. phenytoin, phenobarbital, carbamazepine), rifabutin, others. May cause false (+) cannabis screening test (CEDIA DAU multi-level THC assay).