Efavirenz

Conditions Treated

Efavirenz is used with other medications to treat human immunodeficiency virus (HIV) infection in patients with or without acquired immunodeficiency syndrome (AIDS). Efavirenz is in a class of medications called non-nucleoside reverse transcriptase inhibitors (NNRTIs). It works by slowing the spread of HIV in the body. Efavirenz does not cure HIV infection and may not prevent you from developing HIV-related illnesses. Efavirenz does not prevent you from spreading HIV to other people.

Possible Side Effects

What Side Effects Can This Cause?

Efavirenz may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• upset stomach
• vomiting
• stomach pain
• diarrhea
• indigestion
• drowsiness
• dizziness
• headache
• difficulty concentrating
• confusion
• forgetfulness
• nervousness
• strange thoughts
• abnormally happy mood
• difficulty falling asleep or staying asleep
• unusual dreams
• pain

Some side effects can be serious. If you experience any of the following symptoms or those mentioned in the SPECIAL PRECAUTIONS section, call your doctor immediately:

• sore throat, cough, fever, chills, or other signs of infection
• rash
• itching
• blisters or sores on skin
• peeling skin
• fainting
• extreme tiredness
• lack of energy
• loss of appetite
• pain in the upper right part of the stomach
• unusual bleeding or bruising
• yellowing of the skin or eyes
• flu-like symptoms
• seizures

Efavirenz may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/Safety/MedWatch] or by phone [1-800-332-1088].

Usage Instructions

How Should This Medication Be Used

Efavirenz comes as a capsule and as a tablet to take by mouth. It is usually taken once a day with plenty of water on an empty stomach. Take efavirenz at around the same time every day. Taking efavirenz at bedtime may make side effects less bothersome. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take efavirenz exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor. Efavirenz controls HIV infection, but does not cure it. Continue to take efavirenz even if you feel well. Do not stop taking efavirenz without talking to your doctor. When your supply of efavirenz starts to run low, get more from your doctor or pharmacist. If you miss doses or stop taking efavirenz, your condition may become more difficult to treat.

What Dietary Instructions Should I Follow

Talk to your doctor about eating grapefruit and drinking grapefruit juice while taking this medication.

Are There Any Special Instructions

Before taking efavirenz, tell your doctor and pharmacist if you are allergic to efavirenz or any other medications. do not take astemizole (Hismanal) (no longer available in the US); cisapride (Propulsid) (no longer available in the US); ergot-type medications such as bromocriptine (Parlodel), cabergoline (Dostinex), dihydroergotamine (D.H.E. 45, Migranal), ergoloid mesylates (Germinal, Hydergine), ergonovine (Ergotrate), ergotamine (Bellergal-S, Cafergot, Ergomar, Wigraine), methylergonovine (Methergine), methysergide (Sansert), and pergolide (Permax); midazolam (Versed); triazolam (Halcion); or voriconazole (Vfend) while taking efavirenz. tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, and nutritional supplements you are taking or plan to take. Be sure to mention any of the following: acetaminophen (Tylenol, others); anticoagulants ('blood thinners') such as warfarin (Coumadin); antidepressants; antifungals such as itraconazole (Sporanox), and ketoconazole (Nizoral); calcium channel blockers such as amlodipine (Norvasc), diltiazem (Cardizem, Dilacor, Tiazac, others), felodipine (Lexxel, Plendil), nifedipine (Adalat, Procardia), nisoldipine (Sular), and verapamil (Calan, Covera, Isoptin, Verelan); chlorpheniramine in over-the-counter cold products; cholesterol-lowering medications (statins); cimetidine (Tagamet); clarithromycin (Biaxin, Prevpac); danazol (Danocrine); dexamethasone (Decadron); erythromycin (E.E.S., E-Mycin, Erythrocin); iron products; isoniazid (INH, Nydrazid); medications for anxiety, mental illness, or pain; medications for HIV or AIDS such as amprenavir (Agenerase), atazanavir (Reyataz); indinavir (Crixivan), lopinavir (in Kaletra), ritonavir (Norvir, in Kaletra) and saquinavir ( Invirase); medications for seizures such as carbamazepine (Tegretol), phenobarbital, and phenytoin (Dilantin, Phenytek); methotrexate (Rheumatrex); methadone (Dolophine); metronidazole (Flagyl); niacin (nicotinic acid); nonsteroidal anti-inflammatory drugs (NSAIDs) such as celecoxib (Celebrex), diclofenac (Voltaren), ibuprofen (Advil, Motrin), naproxen (Aleve, Anaprox, Naprosyn), and piroxicam (Feldene); oral medications for diabetes such as glipizide (Glucotrol, Metaglip) and tolbutamide (Orinase); proton pump inhibitors such as lansoprazole (Prevacid), omeprazole (Prilosec), and pantoprazole (Protonix); quinidine (Quinidex); quinine; rifabutin (Mycobutin); rifampin (Rifadin, Rimactane); sedatives; sertraline (Zoloft); sildenafil (Viagra); sleeping pills; sulfamethoxazole (Bactrim, Septra); tamoxifen (Nolvadex); torsemide (Demadex); tranquilizers; troleandomycin (TAO); or zafirlukast (Accolate). Your doctor may need to change the doses of your medications or monitor you carefully for side effects. tell your doctor what herbal products you are taking, especially products that contain kava or St. John's wort. tell your doctor if you drink or have ever drunk large amounts of alcohol; if you use or have ever used street drugs or have overused prescription medications; or if you have or have ever had seizures; high cholesterol; depression or other mental illness; or heart, liver,or pancreas disease. if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking efavirenz. you should know that efavirenz may make you drowsy, dizzy, or unable to concentrate. Do not drive a car or operate machinery until you know how this medication affects you. ask your doctor about the safe use of alcoholic beverages while you are taking efavirenz. Alcohol can make the side effects from efavirenz worse. you should know that your body fat may increase or move to different areas of your body such as your breasts and upper back. you should know that efavirenz may cause changes in your thoughts, behavior, or mental health. Call your doctor immediately if you develop any of the following symptoms while you are taking efavirenz: depression, thinking about killing yourself or planning or trying to do so, angry or aggressive behavior, hallucinations (seeing things or hearing voices that do not exist), or loss of touch with reality. Be sure your family knows which symptoms may be serious so that they can call your doctor if you are unable to seek treatment on your own.