Efavirenz is indicated in combination with other antiretroviral agents for the treatment of human immunodeficiency virus type 1 infection.

HIV

• Efavirenz should be taken once daily on an empty stomach, preferably before going to bed.
• Recommended adult dose: 600 mg.
• Increase the voriconazole maintenance dose to 400 mg every 12 hours and reduce the Efavirenz dose to 300 mg once daily when using the capsule formulation.
• Pediatric dosage-
• • 10 to less than 15 kg : 200 mg
  • 15 to less than 20kg : 250 mg
  • 20 to less than 25kg : 300 mg
  • 25 to less than 32.5 kg : 350mg
  • 32.5 to less than 40 kg : 400 mg
  • At least 40 kg : 600  mg

Most common adverse reactions (>5%, moderate-severe) are

• rash
• dizziness
• nausea
• headache
• fatigue
• insomnia
• vomiting

Rash	Dizziness	Nausea
Headache	Fatigue	Insomnia (Difficulty in Falling asleep)

• 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. 
• Not recommended with efavirenz / emtricitabine / tenofovir.
• Serious psychiatric symptoms: Immediate medical evaluation is recommended for serious psychiatric symptoms such as severe depression or suicidal ideation
• Nervous system symptoms (NSS): NSS are frequent, 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.
• Pregnancy: Fetal harm can occur when administered to a pregnant woman during the first trimester. Women should be apprised of the potential harm to the fetus.
• 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.
• Rash: Rash usually begins within 1-2 weeks after initiating therapy and resolves within 4 weeks. Discontinue if severe rash develops.
• Convulsions: Use caution in patients with a history of seizures.
• Lipids: Total cholesterol and triglyceride elevations. Monitor before therapy and periodically thereafter.
• Immune reconstitution syndrome: May necessitate further evaluation and treatment. 
• Redistribution/accumulation of body fat: Observed in patients receiving antiretroviral therapy.