Adverse effects of Efavirenz
The most common adverse effects have been rash, dizziness, headache, insomnia and inability to concentrate. Vivid dreams, nightmares and hallucinations also occur frequently. CNS effects tend to occur between 1 and 3 hours after each dose, and often stop within a few weeks. Hypertriglyceridemia has occurred. Fetal abnormalities occurred in pregnant monkeys exposed to efavirenz; the drug should not be given to women who are, or are considering becoming, pregnant. Methadone dosage often needs to be enhanced if efavirenz is used concurrently.