home > drugs a-z list > sustiva (efavirenz) drug center > sustiva (efavirenz) drug - consumer side effects and precautions

Dizziness, trouble sleeping, drowsiness, unusual dreams, and trouble concentrating may frequently occur. These side effects may begin 1-2 days after starting this medication and usually go away in 2-4 weeks. They are also reduced by taking efavirenz on an empty stomach at bedtime. Avoid alcohol and street drugs while taking efavirenz. They may worsen these side effects.

Tiredness, headache, nausea, vomiting, and diarrhea may also occur.

If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Infrequently, serious psychiatric symptoms may occur during efavirenz treatment, although it is unclear if they are caused by efavirenz. These effects may be seen especially in people who have mental/mood conditions. Tell your doctor immediately if any of these unlikely but serious side effects occur: mental/mood changes (such as depression, rare thoughts of suicide, nervousness, angry behavior, hallucinations).

Tell your doctor immediately if any of these rare but serious side effects occur: signs of liver problems (such as persistent nausea/vomiting, stomach/abdominal pain, severe tiredness, yellowing eyes/skin, dark urine).

Changes in body fat may occur while you are taking this medication (such as increased fat in the upper back and stomach areas, decreased fat in the arms and legs). The cause and long-term effects of these changes are unknown. Discuss the risks and benefits of treatment with your doctor, as well as the possible use of exercise to reduce this side effect.

Efavirenz can commonly cause a rash that is usually not serious. A rash may occur in the first 2 weeks after starting treatment and if it is not serious, it will usually resolve in 4 weeks. However, you may not be able to tell it apart from a rare rash that could be a sign of a severe reaction. Therefore, seek immediate medical attention if you develop any rash.

A very serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction may include: rash, blisters, peeling skin, fever, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

PRECAUTIONS: Before taking efavirenz, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: mental/mood conditions (such as depression, thoughts of suicide, psychosis), liver problems (such as hepatitis B or C, cirrhosis), drug/substance/alcohol abuse, seizures, high cholesterol/triglyceride levels.

This drug may make you dizzy or drowsy or cause trouble concentrating. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Avoid alcoholic beverages.

A rash may be more common and serious in children taking efavirenz. Report any rash immediately. The doctor may prescribe an antihistamine for your child to take before efavirenz is started. Consult the doctor for more information.

To decrease your risk of spreading HIV disease to others, always use an effective barrier method (latex or polyurethane condoms/dental dams) during all sexual activity. Consult your doctor or pharmacist for more details.

This medication is not recommended for use during pregnancy. It may harm an unborn baby, especially if taken during the first 3 months of pregnancy. Women of childbearing age should have a pregnancy test before starting efavirenz. It is important to prevent pregnancy while taking this medication and for 3 months after treatment. Consult your doctor about using at least 2 reliable forms of birth control (such as condoms with birth control pills) during treatment and for 3 months after the end of treatment. Efavirenz decreases the effectiveness of hormonal birth control products, so you must always use a barrier protection with these products. If you become pregnant or think you may be pregnant, tell your doctor immediately. Discuss the risks and benefits of HIV treatment and alternatives to efavirenz during pregnancy to decrease the risk of HIV transmission to the baby.

It is not known if efavirenz passes into breast milk. Because breast milk can transmit HIV, do not breast-feed.