Serious adverse psychiatric symptoms (aggressive behavior, nonfatal suicide attempts, paranoid reactions, severe depression, suicidal ideation) reported rarely in clinical studies. Dizziness or insomnia reported frequently; abnormal dreams, hallucinations, or impaired concentration also reported. Seizures reported rarely (caution if used in history of seizures). CNS effects may be potentiated when used with other sedative drugs or ethanol. Patients may develop immune reconstitution syndrome. High potential for interactions with CYP3A4 inhibitors, moderate or strong CYP3A4 inducers and major CYP3A4 substrates. May cause fetal harm. Pregnancy should be avoided. Rash (maculopapular skin eruptions, blistering, moist desquamation, or ulceration, erythema multiforme, and Stevens-Johnson syndrome) reported frequently. Rash reported more frequently in children than in adults. Concomitant use of multiple efavirenz-containing preparations should be avoided. Increases in total serum cholesterol and triglycerides have occurred. Possible redistribution or accumulation of body fat. Use with caution in the elderly due to age-related decreases in hepatic, renal, and/or cardiac function and concomitant disease and drug therapy. Use with caution in hepatic impairment.