What should I tell my health care provider before I take this medicine?

They need to know if you have any of these conditions:

history of a drug or alcohol abuse problem

history of depression or other mental illness

liver disease

seizures

taking any other medicines

an unusual or allergic reaction to efavirenz, other medicines, foods, dyes, or preservatives

pregnant or trying to get pregnant

breast-feeding

How should I use this medicine?

Take this medicine by mouth with a glass of water. Follow the directions on the prescription label. Take this medicine on an empty stomach, at least 30 minutes before or 2 hours after food. Do not take with food. Take your dose at bedtime. Take your medicine at regular intervals. Do not take your medicine more often than directed. For your anti-HIV therapy to work as well as possible, take each dose exactly as prescribed. Do not skip doses or stop your medicine even if you feel better. Skipping doses may make the HIV virus resistant to this medicine and other medicines. Do not stop taking except on your doctor's advice.
Talk to your pediatrician regarding the use of this medicine in children. While this drug may be prescribed for children as young as 3 years old for selected conditions, precautions do apply.
A patient information sheet for the product will be given with each prescription and refill. Read this sheet carefully each time. The sheet may change frequently.
Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.

What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is less than four hours to your next dose, take only that dose and skip the missed dose. Do not take double or extra doses.

What may interact with this medicine?

Do not take this medicine with any of the following medications:

cerviastatin

cisapride

disopyramide

medicines for headaches like dihydroergotamine, ergonovine, ergotamine, methylergonovine

midazolam

pimozide

rifapentine

St. John's Wort

triazolam

voriconazole

This medicine may also interact with the following medications:

amiodarone

clarithromycin

female hormones, like estrogens or progestins and birth control pills, patches, rings, or injections

medicines for blood pressure like diltiazem, nifedipine, verapamil

medicines for cholesterol like simvastatin

medicines for depression, anxiety, or psychotic disturbances

medicines for fungal infections like ketoconazole, itraconazole, and posaconazole

medicines for seizures like carbamazepine, phenobarbital, phenytoin

medicines for sleep

methadone

other medicines for HIV

red yeast rice

rifabutin

rifampin

sirolimus

tacrolimus

warfarin

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What should I watch for while using this medicine?

Visit your doctor or health care professional for regular check ups. Discuss any new symptoms with your doctor. You will need to have important blood work done while on this medicine.
HIV is spread to others through sexual or blood contact. Talk to your doctor about how to stop the spread of HIV.
You may get drowsy or dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medicine affects you. Do not stand or sit up quickly, especially if you are an older patient. This reduces the risk of dizzy or fainting spells. Avoid alcohol and mood altering (street) drugs while taking this medicine because they can make these side effects worse.
Birth control pills may not work properly while you are taking this medicine. Talk to your doctor about using an extra method of birth control. Women who can still have children must use a reliable form of barrier contraception, like a condom or diaphragm.

What side effects may I notice from receiving this medicine?

Side effects that you should report to your doctor or health care professional as soon as possible:

allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue

changes in behavior like severe depression, strange thoughts, thoughts of suicide, or angry behavior

hallucinations

Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):

diarrhea

difficulty sleeping, strange dreams

dizziness

trouble concentrating

unusually tired

upset stomach, vomiting

weight gain around waist, back, or thinning of face, arms, legs

Where should I keep my medicine?

Keep out of the reach of children.
Store at room temperature between 15 and 30 degrees C (59 and 86 degrees F). Throw away any unused medicine after the expiration date.