Efavirenz
Efavirenz (Sustiva)
Efavirenz
(eh- FAH-vih-rehnz)
Pregnancy Category: C Sustiva (Rx)

Classification: Antiviral drug

See Also: See also Antiviral Agents.

Action/Kinetics: A non-nucleoside reverse transcriptase inhibitor of HIV-1. Action is mainly by non-competitive inhibition of HIV-1. Peak plasma levels: 3-5 hr. Steady-state plasma levels: 6-10 days. Highly protein bound. Metabolized by the cytochrome P450 system to inactive metabolites which are excreted in the urine and feces. Will induce its own metabolism. t 1/2, terminal: 52-76 hr after a single dose and 40-55 hr after multiple doses.

Uses: In combination with other antiretroviral drugs to treat HIV-1 infection.

Contraindications: Use as a single agent to treat HIV or added on as a sole agent to a failing regimen. High fat meals (increases absorption).

Special Concerns: HIV-infected mothers should not breastfeed to avoid risking postnatal transmission of HIV infection. Use with caution in impaired hepatic function.

Side Effects: CNS: Delusions, inappropriate behavior (especially in those with a history of mental illness or substance abuse), severe acute depression with suicidal ideation/attempts, dizziness, impaired concentration, somnolence, abnormal dreams, insomnia, fatigue, headache, hypoesthesia, depression, anorexia, nervousness, ataxia, confusion, convulsions, impaired coordination, migraine headaches, neuralgia, paresthesia, peripheral neuropathy, speech disorder, tremor, vertigo, aggravated depression, agitation, amnesia, anxiety, apathy, emotional lability, euphoria, hallucinations, psychosis. Dermatologic: Skin rash, including moist or dry desquamation, ulceration, erythema, pruritus, diffuse maculopapular rash, vesiculation, erythema multiforme. Increased sweating, alopecia, eczema, folliculitis, urticaria. Rarely, Stevens-Johnson syndrome, toxic epidermal necrolysis necrosis requiring surgery, exfoliative dermatitis. GI: N&V;, diarrhea, dyspepsia, abdominal pain, flatulence, dry mouth, pancreatitis. GU: Hematuria, renal calculus. CV: Flushing, palpitations, tachycardia, thrombophlebitis. Musculoskeletal: Arthralgia, myalgia. Ophthalmic: Abnormal vision, diplopia. Miscellaneous: Parosmia, taste perversion, alcohol intolerance, allergic reaction, asthenia, fever, hot flushes, malasie, pain, peripheral edema, syncope, tinnitus, hepatitis, asthma.

Laboratory Test Alterations: AST, ALT, total cholesterol, serum triglycerides.

Overdose Management: Symptoms: Increased nervous system symptoms. Treatment: General supportive measures, including monitoring of vital signs.

Drug Interactions: Astemizole / Inhibition of astemizole metabolism possible cardiac arrhythmias, prolonged sedation, or respiratory depression Cisapride / Inhibition of cisapride metabolism possible cardiac arrhythmias, prolonged sedation, or respiratory depression Clarithromycin / Clarithromycin plasma levels and levels of metabolite; use alternative therapy such as azithromycin CNS depressants / Additive CNS depression Ergot derivatives / Inhibition of ergot metabolism possible cardiac arrhythmias, prolonged sedation, or respiratory depression Midazolam / Inhibition of midazolam metabolism possible cardiac arrhythmias, prolonged sedation, or respiratory depression Ritonavir / Higher frequency of dizziness, nausea, paresthesia, and elevated liver enzymes Triazolam / Inhibition of triazolam metabolism possible cardiac arrhythmias, prolonged sedation, or respiratory depression

How Supplied: Capsules: 50 mg, 100 mg, 200 mg

Dosage
?Capsules HIV-1 infections.
Adults: 600 mg once daily in combination with a protease inhibitor or nucleoside analog reverse transcriptase inhibitors. Children, 3 years and older. 10- < 15 kg: 200 mg once daily; 15- < 20 kg: 250 mg once daily; 20- <han; 25 kg: 300 mg once daily; 25- <han; 32.5 kg: 350 mg once daily; 32.5- < 40 kg: 400 mg once daily; 40 kg or more: 600 mg once daily.