Efavirenz can cause serious, life-threatening side effects. These include serious psychiatric problems and liver problems.
Contact your health care provider right away if you have any of the following symptoms that may signal psychiatric problems:
- Severe depression.
- Suicidal thoughts.
- Strange thoughts.
- Angry behavior.
Some people taking efavirenz have experienced serious liver problems. This usually occurred in people with a chronic liver disease (such as hepatitis infection), but there have also been a few reports in people without any existing liver disease. Tell your health care provider if you notice any side effects while taking efavirenz.
Women should not become pregnant while taking efavirenz and for 12 weeks after stopping the drug. Serious birth defects have been seen in the babies of animals and women treated with efavirenz during pregnancy. Whether efavirenz caused the birth defects is unknown.
While taking efavirenz, it is important to keep all of your appointments with your health care provider.
What is efavirenz?
Efavirenz is a prescription medicine approved by the U.S. Food and Drug Administration (FDA) for the treatment of HIV infection in adults. Efavirenz is also approved for use in children 3 months of age and older who weigh at least 3.5 kilograms. Efavirenz is always used in combination with other anti-HIV medicines.
Efavirenz is a type of anti-HIV medicine called a non-nucleoside reverse transcriptase inhibitor (NNRTI). NNRTIs work by binding to and blocking HIV reverse transcriptase, an HIV enzyme. This prevents HIV from replicating and lowers the amount of HIV in the blood.
Efavirenz does not cure HIV/AIDS. It is not known if efavirenz reduces the risk of passing HIV to other people.
What should I tell my health care provider before taking efavirenz?
Before taking efavirenz, tell your health care provider:
- If you are allergic to efavirenz or any other medicines.
- If you have liver problems or hepatitis.
- If you have ever had mental illness or are using drugs or alcohol.
- If you have ever had seizures or are taking medicine for seizures.
- If you are pregnant or plan to become pregnant. Women should not become pregnant while taking efavirenz and for 12 weeks after stopping the drug. Serious birth defects have been seen in the babies of animals and women treated with efavirenz during pregnancy. Whether efavirenz caused the birth defects is unknown. Do not breastfeed if you are infected with HIV or are taking efavirenz.
- If you are taking birth control pills. Efavirenz can reduce the effectiveness of birth control pills.
- About other prescription and nonprescription medicines, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Efavirenz may affect the way other medicines or products work, and other medicines and products may affect how efavirenz works. Taking efavirenz together with certain medicines or products may cause serious and/or life-threatening side effects.
How should I take efavirenz?
Efavirenz comes in two forms:
- 200-mg and 50-mg capsules (brand name: Sustiva).
- 600-mg tablets (brand name: Sustiva).
Take efavirenz according to your health care provider’s instructions.
Take efavirenz on an empty stomach and without food, preferably at bedtime. Swallow efavirenz with water.
For adults and pediatric patients who cannot swallow capsules or tablets, the capsule contents can be taken by mixing the contents with a small amount (1 to 2 teaspoons) of food or infant formula. (Use of infant formula should be considered only for young infants who cannot reliably eat solid foods.) After mixing and taking the efavirenz-food or –formula mixture, an additional small amount (2 teaspoons) of food or formula should be added to the empty mixing container, stirred, and then taken. No additional food should be eaten 2 hours after taking efavirenz.
Always take efavirenz in combination with other anti-HIV medicines.
If you take too much efavirenz, contact your local poison control center (1-800-222-1222) or go to the nearest hospital emergency room right away.
For more information on how to take efavirenz, see the FDA drug label from DailyMed. (DailyMed is a federal website that includes the most recent drug labels submitted to FDA.)
What should I do if I forget a dose?
Take the missed dose as soon as you remember it. But if it is almost time for your next dose, skip the missed dose and just take your next dose at the regular time. Do not take two doses at the same time to make up for a missed dose.
What side effects can efavirenz cause?
Efavirenz can cause serious, life-threatening side effects. These include serious psychiatric problems and liver problems. (See the WARNING above.)
Other possible side effects of efavirenz include:
- Rash. If you develop a rash, call your health care provider right away. Rash may be a serious problem in some children.
- Changes in body fat (lipodystrophy).
- Increased levels of cholesterol and triglycerides (hyperlipidemia).
- Changes in the immune system (immune reconstitution inflammatory syndrome).
Tell your health care provider if you have any side effect that bothers you or that does not go away.
These are not all the possible side effects of efavirenz. Ask your health care provider or pharmacist for more information on possible side effects of efavirenz.
How should efavirenz be stored?
- Store efavirenz in the original bottle at room temperature, 59°F to 86°F (15°C to 30°C).
- Safely throw away efavirenz that is no longer needed or expired (out of date).
- Keep efavirenz and all medicines out of reach of children.
Where can I find more information about efavirenz?
More information about efavirenz is available:
Last Reviewed: May 3, 2013
Last Updated: May 3, 2013