Efavirenz

Pronunciation: EF-a-VIR-enz
Generic Name: Efavirenz
Brand Name: Sustiva

Efavirenz is used for:

Treating HIV infection in combination with other medicines. If Efavirenz is taken alone to treat HIV, it may stop working.

Efavirenz is a nonnucleoside reverse transcriptase inhibitor (NNRTI). It works by blocking the growth of HIV.

Do NOT use Efavirenz if:

• you are allergic to any ingredient in Efavirenz or have developed red, swollen, blistered, or peeling skin after taking any ingredient in Efavirenz


• you have moderate to severe liver problems


• you are taking astemizole, bepridil, cabazitaxel, cisapride, an ergot medicine (eg, dihydroergotamine, ergotamine, methylergonovine), lurasidone, midazolam, nevirapine, pimozide, St. John's wort, terfenadine, ticagrelor, triazolam, or vandetanib.


• you are taking another medicine that contains efavirenz

Contact your doctor or health care provider right away if any of these apply to you.

Before using Efavirenz:

Some medical conditions may interact with Efavirenz. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

• if you are pregnant, planning to become pregnant, or are breast-feeding


• if you are of childbearing age


• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement


• if you have allergies to medicines, foods, or other substances


• if you have high cholesterol, kidney problems, or a history of liver problems (eg, hepatitis, abnormal liver function tests)


• if you have a history of seizures, mental or mood problems (eg, depression), or suicidal thoughts or actions


• if you drink alcohol or have a history of alcohol or other substance abuse or dependence

Some MEDICINES MAY INTERACT with Efavirenz. Tell your health care provider if you are taking any other medicines, especially any of the following:

• Astemizole, bepridil, cisapride, pimozide, or terfenadine because serious heart problems (eg, irregular heartbeat) may occur


• Midazolam or triazolam because serious side effects, such as prolonged sedation or breathing problems, may occur


• Ergot medicines (eg, dihydroergotamine, ergotamine, methylergonovine) because serious blood flow problems may occur


• Nevirapine, rifamycins (eg, rifampin), or St. John's wort because they may decrease Efavirenz's effectiveness


• HIV protease inhibitors (eg, amprenavir, atazanavir, ritonavir) or warfarin because their effectiveness may be decreased or the risk of their side effects may be increased by Efavirenz


• Azole antifungals (eg, itraconazole, posaconazole, voriconazole), bupropion, cabazitaxel, calcium channel blockers (eg, diltiazem, nifedipine, verapamil), carbamazepine, cyclosporine, hepatitis C virus (HCV) protease inhibitors (eg, boceprevir), HMG-CoA reductase inhibitors (eg, atorvastatin), hormonal contraceptives (eg, birth control pills, etonogestrel), ixabepilone, lurasidone, certain macrolide antibiotics (eg, clarithromycin), maraviroc, methadone, phenobarbital, phenytoin, rifabutin, sertraline, sirolimus, tacrolimus, ticagrelor, ulipristal, or vandetanib because their effectiveness may be decreased by Efavirenz


• Medicines that may harm the liver (eg, acetaminophen, isoniazid, ketoconazole, certain medicines for HIV infection, methotrexate) because the risk of liver side effects may be increased. Ask your doctor if you are unsure if any of your medicines might harm the liver

This may not be a complete list of all interactions that may occur. Ask your health care provider if Efavirenz may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

How to use Efavirenz:

Use Efavirenz as directed by your doctor. Check the label on the medicine for exact dosing instructions.

• An extra patient leaflet is available with Efavirenz. Talk to your pharmacist if you have questions about this information.


• Take Efavirenz by mouth on an empty stomach at least 1 hour before or 2 hours after eating. Taking Efavirenz with food, especially with a high-fat meal, may lead to increased blood levels of Efavirenz. This may increase your risk of side effects.


• Take Efavirenz with a full glass of water (8 oz/240 mL).


• Take Efavirenz at the same time(s) every day, preferably at bedtime unless otherwise directed by your doctor.


• Continue to use Efavirenz even if you feel well. Do not miss any doses.


• If you miss a dose of Efavirenz, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.

Ask your health care provider any questions you may have about how to use Efavirenz.

Important safety information:

• Efavirenz may cause drowsiness, dizziness, or trouble concentrating. These effects may be worse if you take it with alcohol or certain medicines. Use Efavirenz with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.


• Do not drink alcohol or use medicines that may cause drowsiness (eg, sleep aids, muscle relaxers) while you are using Efavirenz; it may add to their effects. Ask your pharmacist if you have questions about which medicines may cause drowsiness.


• Efavirenz may cause dizziness, drowsiness, trouble sleeping, trouble concentrating, or unusual dreams. These effects usually go away after you have taken Efavirenz for about 2 to 4 weeks. Taking it at bedtime may help to decrease these effects. Check with your doctor if they continue or are severe.


• Do NOT take more than the recommended dose, change your dose, or stop taking Efavirenz without checking with your doctor. Taking more than the recommended dose may not provide additional benefits and may increase the risk of side effects.


• Efavirenz may improve immune system function. This may reveal hidden infections in some patients. Tell your doctor right away if you notice symptoms of infection (eg, fever, sore throat, weakness, cough, shortness of breath) after you start Efavirenz.


• Changes in body fat (eg, an increased amount of fat in the upper back, neck, breast, and trunk, and loss of fat from the legs, arms, and face) may occur in some patients taking Efavirenz. The cause and long-term effects of these changes are unknown. Discuss any concerns with your doctor.


• Efavirenz is not a cure for HIV infection. Patients may still get illnesses and infections associated with HIV. Remain under the care of your doctor.


• Efavirenz does not stop the spread of HIV to others through blood or sexual contact. Use barrier methods of birth control (eg, condoms) if you have HIV infection. Do not share needles, injection supplies, or items like toothbrushes or razors.


• Efavirenz will not prevent you from getting sexually transmitted diseases (STDs). Always use a condom during sexual intercourse.


• If your health changes, check with your doctor.


• When your medicine supply is low, get more from your doctor or pharmacist as soon as you can. Do not stop taking Efavirenz, even for a short period of time. If you do, the virus may grow resistant to the medicine and become harder to treat.


• Efavirenz may interfere with certain lab tests, including cannabinoids/marijuana false-positive result. Be sure your doctor and lab personnel know you are taking Efavirenz.


• Talk to your doctor about whether you should have a pregnancy test before you begin taking Efavirenz.


• If you may become pregnant, you must use an effective form of birth control while you take Efavirenz and for 12 weeks after you stop taking it. Hormonal birth control (eg, birth control pills) may not work as well while you are using Efavirenz. You should always use a barrier form of birth control (eg, condoms), even if you already use a hormonal birth control method. If you have questions about effective birth control, talk with your doctor.


• Lab tests, including liver function and cholesterol and triglyceride levels, may be performed while you use Efavirenz. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.


• Use Efavirenz with caution in the ELDERLY; they may be more sensitive to its effects.


• Efavirenz should be used with extreme caution in CHILDREN younger than 3 years old and in children who weigh less than 13 kg (28.6 lb); safety and effectiveness in these children have not been confirmed.


• PREGNANCY and BREAST-FEEDING: Efavirenz may cause harm to the fetus. Do not become pregnant while you are taking it or for 12 weeks after you stop taking it. If you think you may be pregnant, contact your doctor. You will need to discuss the benefits and risks of using Efavirenz while you are pregnant. It is not known if Efavirenz is found in breast milk. Mothers infected with HIV should not breast-feed. There is a risk of passing the HIV infection or Efavirenz to the baby.

Possible side effects of Efavirenz:

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:

Abnormal dreams; diarrhea; dizziness; drowsiness; headache; nausea; tiredness; trouble concentrating; trouble sleeping; upset stomach; vomiting.

Seek medical attention right away if any of these SEVERE side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); burning, numbness, or tingling; change in personality; confusion; cough; delusions; fainting; fever, chills, or persistent sore throat; hallucinations; irregular heartbeat; memory loss; mental, mood, or behavior changes (eg, abnormal thoughts, agitation, aggression, anxiety, depression, nervousness, paranoia); mouth sores; rash with or without fever; red, swollen, blistered, or peeling skin; seizures; severe or persistent tiredness or weakness; severe stomach pain; shortness of breath; suicidal thoughts or behaviors; symptoms of liver problems (eg, dark urine, loss of appetite, pale stools, yellowing of the skin or eyes); vision changes.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. To report side effects to the appropriate agency, please read the Guide to Reporting Problems to FDA.

See also: Efavirenz side effects (in more detail)

If OVERDOSE is suspected:

Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center, or emergency room immediately. Symptoms may include hallucinations; muscle twitching; severe dizziness, drowsiness, or coordination problems; trouble concentrating; trouble sleeping.

Proper storage of Efavirenz:

Store Efavirenz at 77 degrees F (25 degrees C). Brief storage at temperatures between 59 and 86 degrees F (15 and 30 degrees C) is permitted. Store in a tightly closed container away from heat, moisture, and light. Do not store in the bathroom. Keep Efavirenz out of the reach of children and away from pets.

General information:

• If you have any questions about Efavirenz, please talk with your doctor, pharmacist, or other health care provider.


• Efavirenz is to be used only by the patient for whom it is prescribed. Do not share it with other people.


• If your symptoms do not improve or if they become worse, check with your doctor.


• Check with your pharmacist about how to dispose of unused medicine.

This information is a summary only. It does not contain all information about Efavirenz. If you have questions about the medicine you are taking or would like more information, check with your doctor, pharmacist, or other health care provider.

Issue Date: February 1, 2012

Database Edition 12.1.1.002

Copyright © 2012 Wolters Kluwer Health, Inc.

More Efavirenz resources

• Efavirenz Side Effects (in more detail)
• Efavirenz Use in Pregnancy & Breastfeeding
• Efavirenz Drug Interactions
• Efavirenz Support Group
• 2 Reviews for Efavirenz - Add your own review/rating

• Efavirenz Professional Patient Advice (Wolters Kluwer)


• Efavirenz Monograph (AHFS DI)


• efavirenz Advanced Consumer (Micromedex) - Includes Dosage Information


• Sustiva Prescribing Information (FDA)


• Sustiva Consumer Overview

Compare Efavirenz with other medications

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• Occupational Exposure