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Drugs reference index «Sustiva»



Generic name: EfavirenzBrand names: Sustiva

Why is Sustiva prescribed?

Sustiva is one of the growing number of drugs used to fight HIV infection. HIV, the human immunodeficiency virus, weakens the immune system until it can no longer fight off infections, leading to the fatal disease known as AIDS (acquired immune deficiency syndrome).

Like other drugs for HIV, Sustiva works by impairing the virus's ability to multiply. However, when taken alone it may prompt the virus to become resistant. Sustiva is therefore always taken with at least one other HIV medication, such as Retrovir or Crixivan. Even when used properly, it may remain effective for only a limited time.

Most important fact about Sustiva

Though Sustiva can slow the progress of HIV, it is not a cure. HIV-related infections remain a danger, so frequent checkups and tests are still advisable.

How should you take Sustiva?

Be sure to take Sustiva every day, exactly as prescribed. Take the drug on an empty stomach, preferably at bedtime. Taking it at bedtime reduces the likelihood of side effects such as dizziness, impaired concentration, weakness, abnormal dreams, or drowsiness.

  • If you miss a dose...Take it as soon as you remember. If it is almost time for the next dose, skip the one you missed and go back to your regular schedule. Do not double the dose.
  • Storage instructions...Store at room temperature.

What side effects may occur?

Side effects cannot be anticipated. If any develop or change in intensity, inform your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking Sustiva.

  • Side effects may include:Abnormal dreaming, abnormal thinking, amnesia, agitation, confusion, cough, diarrhea, dizziness, drowsiness, fatigue, feelings of well-being, fever, hallucinations, headache, impaired concentration, insomnia, loss of identity, nausea, skin rash, vomiting

Why should Sustiva not be prescribed?

Do not take Sustiva with the following medications. The combination could cause serious—even life-threatening—effects such as heart irregularities or disrupted breathing.

Ergot-based migraine medications such as D.H.E. 45, Ergostat, and SansertMidazolam (Versed)Triazolam (Halcion)

If Sustiva gives you an allergic reaction, you cannot continue using it.

Special warnings about Sustiva

If you develop delusions, inappropriate behavior, severe depression, or suicidal thoughts, call your doctor immediately. Sustiva could be the cause, and may have to be discontinued. If you've suffered mental illness, substance abuse, or depression in the past, make sure the doctor is aware of this before therapy begins.

Roughly half the people taking Sustiva develop symptoms such as dizziness, lack of concentration, or drowsiness. Avoid driving or operating machinery while these symptoms occur. They are likely to improve with continued therapy, generally within 2 to 4 weeks.

One of the most common side effects of Sustiva is skin rash. Most rashes usually clear up on their own. However, for roughly 1 patient in 100, the drug causes a severe rash associated with blistering, skin peeling, and fever. If you develop this type of rash, call your doctor. You may have to stop taking Sustiva.

When first beginning therapy with Sustiva, your immune system may have an inflammatory reaction to other infections in your body, such as pneumonia or tuberculosis.

Because Sustiva has occasionally caused convulsions, use the drug with caution if you have a history of seizures. Your doctor will monitor you closely during treatment with Sustiva if you're also taking antiseizure drugs such as phenytoin (Dilantin), carbamazepine (Tegretol), or phenobarbital.

Another side effect seen in some people receiving drugs for HIV is a redistribution of body fat, leading to extra fat around the middle, a "buffalo hump" on the back, and wasting in the arms, legs, and face. Researchers don't know whether this represents a long-term health problem or not.

In a few patients, Sustiva has toxic effects on the liver. If you've had hepatitis or must take other medications that could damage the liver, your doctor will probably check your liver function regularly.

Sustiva also has a tendency to raise cholesterol levels in some patients. If you have a cholesterol problem, your doctor may test for this as well.

Remember that Sustiva does not completely eliminate HIV from the body. The virus can still be passed to others during sex or through blood contamination.

Possible food and drug interactions when taking Sustiva

Be sure to avoid combining Sustiva with Versed, Halcion, or any of the migraine medications listed under "Why should Sustiva not be prescribed?"

If Sustiva is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining Sustiva with the following:

AlcoholAmprenavir (Agenerase)AtazanavirCarbamazepine (Tegretol)Clarithromycin (Biaxin)Indinavir (Crixivan)Itraconazole (Sporanox)Ketoconazole (Nizoral)Methadone (Dolophine)Nelfinavir (Viracept)Oral Contraceptives containing ethinyl estradiol, such as Estinyl, Ovcon, and OvralPhenobarbitalPhenytoin (Dilantin)Rifabutin (Mycobutin)Rifampin (Rifadin and Rimactane)Ritonavir (Norvir)Saquinavir (Fortovase and Invirase)St. John's WortVoriconazole (antifungal)Warfarin (Coumadin)

Special information if you are pregnant or breastfeeding

When taken in the first trimester, Sustiva may cause harm to a developing baby. Therefore, Sustiva should not be taken during pregnancy. Before you begin Sustiva therapy, your doctor will test to make sure that you're not pregnant. While taking the drug, you should use both a barrier type of contraceptive and a second method such as contraceptive pills.

Avoid breastfeeding. HIV infection can be passed to a nursing infant through breast milk.

Recommended dosage for Sustiva


The recommended dose is 600 milligrams once a day, in combination with other HIV medications.


For children 3 years of age and older, weighing between 22 and 88 pounds, the recommended dose is based upon weight. Children weighing more than 88 pounds receive the 600-milligram adult dose.


Any medication taken in excess can have serious consequences. If you suspect an overdose, seek medical attention immediately.

  • Symptoms of Sustiva overdose may include:Involuntary muscle contractions, increased nervous system symptoms such as dizziness, weakness, confusion, impaired concentration, and hallucinations
  • Sustiva Prescribing Information (FDA)
  • Sustiva Consumer Overview
  • Sustiva Advanced Consumer (Micromedex) - Includes Dosage Information
  • Sustiva MedFacts Consumer Leaflet (Wolters Kluwer)
  • Efavirenz Professional Patient Advice (Wolters Kluwer)