Generic name: Efavirenz.

Sustiva is a non-nucleoside reverse transcriptase inhibitor (NNRTI) of HIV. It works by inhibiting the reverse transcriptase (RT) enzyme necessary for the reproduction of HIV in body cells. Used in combination with other anti-HIV drugs for people who do not respond to singledrug therapy.

Quick Facts About Sustiva


Used to slow the progress of the human immunodeficiency virus (HIV), which can lead to acquired immunodeficiency syndrome (AIDS).

Sustiva Dosage

Take exactly as prescribed. Take at bedtime if you experience dizziness or trouble concentrating. Take with water, juice, milk, or soda. May take with or without a low-fat meal. Do not share Sustiva, and do not increase prescribed dose.

  • Usual adult dose: 600 milligrams once per day.
  • Usual child dose: doctor will prescribe dose based on child’s weight in children able to swallow capsules.
  • Missed dose: missed doses can cause resistance to Sustiva. Take as soon as possible, unless almost time for next dose. In that case, do not take missed dose; go back to regular schedule. Do not double doses.

Sustiva Side Effects

Overdose symptoms:

none reported; however, if you suspect an overdose, immediately seek medical attention.

More common side effects: difficulty concentrating, dizziness, drowsiness, insomnia, skin rash, tiredness, unusual dreams. Side effects usually appear within first few days of treatment and rarely last longer than 2 to 4 weeks. Taking medication at bedtime is recommended during this period. Children — skin rash.

Less common Sustiva side effects: diarrhea, difficulty thinking clearly, headache, mood changes, upset stomach, vomiting.


Taking Sustiva with certain drugs could be dangerous or life-threatening. Do not combine with: astemizole (Hismanal); cisapride (Propulsid); ergot derivatives such as Wigraine and Cafergot; midazolam (Versed); triazolam (Halcion).

Inform your doctor before combining Sustiva with:

any over-the-counter or nonprescription medications; clarithromycin (Biaxin); indinavir (Crixivan); saquinavir (Invirase).

Alcohol may increase side effects; do not drink while taking Sustiva.

Special Cautions

May cause birth defects. If pregnant or planning to become pregnant, inform your doctor immediately. Do not breastfeed; HIV appears in breast milk and could affect a nursing infant.

No special precautions apply to seniors.

Children: rash may indicate a serious problem. Contact your child’s doctor immediately if you notice rash or any other side effects.

  • Contact your doctor immediately if you experience delusions, unusual behavior, the sudden onset of depression, or any other unusual side effects. Rash may develop; contact doctor immediately if uncomfortable or accompanied by skin blistering.
  • Long-term effects of medication still are not known. Since the HIV virus remains in the body, risk is still present for complications, including opportunistic infections such as pneumonia, tuberculosis, and fungal infection. It is important to remain under the care of a doctor and go to follow-up appointments.
  • Inform your doctor before treatment if you have: liver disease (especially cirrhosis); hepatitis; or a history of mental illness or substance or alcohol abuse.
  • Does not reduce risk of transmitting HIV to others through sexual contact or blood contamination. Always use condoms and never share needles or equipment for injections with other people.
  • May impair your ability to drive a car or operate machinery. Do not take part in any activity that requires mental alertness until adjusted to medication.
  • Doctor should monitor cholesterol levels during Sustiva therapy.

Note: provides accurate and independent information prescription pills, over-the-counter medicines and natural products. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment. If you have questions about  dosage, or Sustiva side effects, please contact your healthcare provider