efavirenz

What is the most important information I should know about efavirenz?

What is efavirenz?

Efavirenz is an antiviral medicine that prevents human immunodeficiency virus (HIV) from multiplying in your body.

Efavirenz is used to treat HIV, the virus that can cause acquired immunodeficiency syndrome (AIDS). Efavirenz is for adults and children who are at least 3 months old and weigh at least 8 pounds. Efavirenz is not a cure for HIV or AIDS.

Efavirenz may also be used for purposes not listed in this medication guide.

What should I discuss with my healthcare provider before taking efavirenz?

Do not take with Atripla (combination efavirenz, emtricitabine, and tenofovir), unless your doctor tells you to.

Tell your doctor if you have ever had:

• liver disease (including hepatitis B or C);
• long QT syndrome;
• a seizure;
• mental illness or psychosis;
• heart disease; or
• if you drink large amounts of alcohol or have a history of injection drug use.

Hormonal contraception (birth control pills, injections, implants, skin patches, and vaginal rings) may not be effective enough to prevent pregnancy while you are taking efavirenz.

HIV can be passed to your baby if the virus is not controlled during pregnancy. Your name may be listed on a registry to track any effects of antiviral medicine on the baby.

How should I take efavirenz?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Read and carefully follow any Instructions for Use provided with your medicine. Ask your doctor or pharmacist if you do not understand these instructions.

If you cannot swallow a capsule whole, open it and sprinkle the medicine into a spoonful of applesauce, yogurt, grape jelly, or infant formula (if you are giving the medicine to a baby). Swallow the mixture right away. Do not save it for later use.

After taking efavirenz using the sprinkle method, do not eat for the next 2 hours. If you give efavirenz mixed with infant formula to a baby, do not feed more formula for at least 2 hours afterward.

Efavirenz doses are based on weight in children. Your child's dose needs may change if the child gains or loses weight.

You will need frequent medical tests.

Take efavirenz regularly to get the most benefit. Skipping doses may increase the risk of your virus becoming resistant to antiviral medicine.

This medicine may affect a drug-screening urine test and you may have false results. Tell the laboratory staff that you use efavirenz.

Use all HIV medications as directed and read all medication guides you receive. Do not change your dose or dosing schedule without your doctor's advice. Every person with HIV should remain under the care of a doctor.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

Get your prescriptions refilled before you run out of medicine completely.

What happens if I overdose?

What should I avoid while taking efavirenz?

Using this medicine will not prevent your disease from spreading. Do not have unprotected sex or share razors or toothbrushes. Talk with your doctor about safe ways to prevent HIV transmission during sex. Sharing drug or medicine needles is never safe, even for a healthy person.

What are the possible side effects of efavirenz?

• a seizure;
• hallucinations, trouble concentrating, trouble speaking or moving (these symptoms may occur months or years after you start taking efavirenz);
• nervous system problems --dizziness, drowsiness, confusion, trouble concentrating, strange dreams, insomnia, or problems with speech, balance, or muscle movement;
• serious psychiatric symptoms --anxiety, paranoia, unusual behavior, feeling sad or hopeless, hallucinations, suicidal thoughts; or
• liver problems --nausea, stomach pain, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);

Psychiatric symptoms or nervous system problems may happen even months or years after you have been taking efavirenz.

Efavirenz affects your immune system, which may cause certain side effects (even weeks or months after you've taken this medicine). Tell your doctor if you have:

• signs of a new infection --fever, night sweats, swollen glands, cold sores, cough, wheezing, diarrhea, weight loss;
• trouble speaking or swallowing, problems with balance or eye movement, weakness or prickly feeling; or
• swelling in your neck or throat (enlarged thyroid), menstrual changes, impotence.

Common side effects may include:

• nausea, vomiting;
• dizziness, drowsiness, trouble concentrating;
• rash;
• headache, tired feeling;
• sleep problems (insomnia), strange dreams; or
• changes in the shape or location of body fat (especially in your arms, legs, face, neck, breasts, and waist).

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect efavirenz?

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Other drugs may affect efavirenz, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Where can I get more information?

Your pharmacist can provide more information about efavirenz.