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Drugs reference index «Sustiva»



Generic Name: efavirenz (Oral route)


Commonly used brand name(s):

In the U.S.

  • Sustiva

Available Dosage Forms:

  • Capsule
  • Tablet

Therapeutic Class: Antiretroviral Agent

Pharmacologic Class: Non-Nucleoside Reverse Transcriptase Inhibitor

Uses For Sustiva

Efavirenz is used with other medicines in the treatment of the infection caused by the human immunodeficiency virus (HIV). HIV is the virus that causes acquired immune deficiency syndrome (AIDS).

Efavirenz will not cure or prevent HIV infection or AIDS; however, it helps keep HIV from reproducing and appears to slow down the destruction of the immune system. This may help delay the development of problems that usually result from AIDS or HIV disease. Efavirenz will not keep you from spreading HIV to other people. People who receive this medicine may continue to have some of the problems usually related to AIDS or HIV disease.

This medicine is available only with your doctor's prescription.

Before Using Sustiva

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:


Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


Appropriate studies have not been performed on the relationship of age to the effects of efavirenz in children below 3 years of age or those who weigh less than 13 kilograms (kg). Safety and efficacy have not been established.


Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of efavirenz in the elderly. However, elderly patients are more likely to have age-related kidney, liver, or heart problems, which may require an adjustment in the dose for patients receiving efavirenz.


Pregnancy CategoryExplanation
All TrimestersDStudies in pregnant women have demonstrated a risk to the fetus. However, the benefits of therapy in a life threatening situation or a serious disease, may outweigh the potential risk.

Breast Feeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with Medicines

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

  • Astemizole
  • Bepridil
  • Cisapride
  • Dihydroergotamine
  • Ergoloid Mesylates
  • Ergonovine
  • Ergotamine
  • Methylergonovine
  • Methysergide
  • Midazolam
  • Pimozide
  • St John's Wort
  • Triazolam

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Amprenavir
  • Cyclosporine
  • Etravirine
  • Fosamprenavir
  • Itraconazole
  • Maraviroc
  • Posaconazole
  • Rifabutin
  • Rifampin
  • Rifapentine
  • Sirolimus
  • Tacrolimus
  • Tolvaptan
  • Voriconazole

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Atazanavir
  • Atorvastatin
  • Bupropion
  • Carbamazepine
  • Caspofungin
  • Clarithromycin
  • Darunavir
  • Diltiazem
  • Etonogestrel
  • Indinavir
  • Ketoconazole
  • Lopinavir
  • Methadone
  • Norgestimate
  • Pravastatin
  • Ritonavir
  • Saquinavir
  • Sertraline
  • Simvastatin

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

  • Alcohol or drug abuse, history of or
  • Mental illness, history of—May increase the chance of having serious psychiatric side effects.
  • Hepatitis B or C, history of or
  • Liver disease—Use with caution. Efavirenz may cause unwanted effects in the liver.
  • Hypersensitivity reactions (e.g., Stevens-Johnson syndrome, erythema multiforme, toxic skin eruptions), history of—Should not be used in patients with this condition.
  • Seizures, history of—Use with caution. May increase chances of convulsions occurring.

Proper Use of Sustiva

Take this medicine exactly as directed by your doctor. Do not take it more often, and do not take it for a longer time than your doctor ordered. Also, do not stop taking this medicine without checking with your doctor first. When your supply of this medicine is running low, contact your doctor or pharmacist ahead of time. Do not allow yourself to run out of this medicine.

This medicine comes with a patient information insert. Read and follow the instructions in the insert carefully. Ask your doctor if you have any questions.

Keep taking efavirenz for the full time of treatment even if you begin to feel better. It is also important that you continue taking all other medicines for HIV infection your doctor has instructed you to take. Efavirenz will not work if it is taken alone. It must be taken with other HIV medication.

Efavirenz should be taken on an empty stomach because the amount of efavirenz absorbed into the body may be increased when taken with food, which might increase the chance of side effects.

Take efavirenz at bedtime, especially during the first 2 to 4 weeks, to lessen central nervous system (CNS) side effects that may occur with this medicine. These effects usually lessen after you have been taking this medicine for awhile.


The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage form (capsules or tablets):
    • For treatment of HIV infection:
      • Adults—600 milligrams (mg) once a day, taken with other medicines.
      • Children 3 years of age and older (by weight)—
        • 10 to 15 kilograms (22 to 33 pounds) of body weight: 200 mg once a day, taken with other medicines.
        • 15 to 20 kilograms (33 to 44 pounds) of body weight: 250 mg once a day, taken with other medicines.
        • 20 to 25 kilograms (44 to 55 pounds) of body weight: 300 mg once a day, taken with other medicines.
        • 25 to 32.5 kilograms (55 to 71.5 pounds) of body weight: 350 mg once a day, taken with other medicines.
        • 32.5 to 40 kilograms (71.5 to 88 pounds) of body weight: 400 mg once a day, taken with other medicines.
        • 40 kilograms (88 pounds) of body weight or over: 600 mg once a day, taken with other medicines.
      • Children up to 3 years of age—Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.


Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Precautions While Using Sustiva

It is very important that your doctor check the progress of you or your child at regular visits, to make sure this medicine is working properly. Blood tests may be needed to check for unwanted effects.

Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant. You should not become pregnant while you are taking this medicine and for 12 weeks after stopping it. If you think you have become pregnant while using the medicine, tell your doctor right away. Your doctor may want you to join a pregnancy registry for patients taking an anti-HIV medicine.

You should not breastfeed if you have HIV or AIDS, because you may give the infection to your baby through your breast milk.

Do not use this medicine if you are also using Atripla®, astemizole (Hismanal®), bepridil (Vascor®), cisapride (Propulsid®), ergot medicines (e.g., dihydroergotamine, ergonovine, ergotamine, methylergonovine, Cafergot®, or Wigraine®), midazolam (Versed®), pimozide (Orap®), triazolam (Halcion®), or voriconazole (Vfend®).

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal (e.g., St. John's wort) or vitamin supplements.

This medicine may cause some people to become dizzy, lightheaded, drowsy, or less alert than they are normally. Even if taken at bedtime, it may cause some people to feel drowsy or less alert on arising. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are not alert.

Check with your doctor before taking efavirenz with alcohol or other medicines that affect the central nervous system (CNS). The use of alcohol or other medicines that affect the CNS with efavirenz may worsen the side effects of this medicine, such as dizziness, poor concentration, drowsiness, unusual dreams, and trouble with sleeping. Some examples of medicines that affect the CNS are antihistamines or medicine for allergies or colds; sedatives, tranquilizers, or sleeping medicine; medicine for depression; medicine for anxiety; prescription pain medicine or narcotics; medicine for attention deficit and hyperactivity disorder; medicine for seizures or barbiturates; muscle relaxants; or anesthetics, including some dental anesthetics.

This medicine may increase your risk of having serious mental or behavioral problems. Tell your doctor if you develop any mood changes, strange thoughts, or any unusual behavior while you are using this medicine.

When you start taking HIV medicines, your immune system may get stronger. If you have certain infections, such as pneumonia or tuberculosis, you may notice new symptoms when your body tries to fight them. If this occurs, be sure to tell your doctor.

Efavirenz may cause you to have excess body fat. Tell your doctor if you notice changes in your body shape, such as an increased amount of fat in the upper back and neck, or around the chest and stomach area. You might also lose fat from the legs, arms, and face.

This medicine will not keep you from giving HIV to your partner during sex. Make sure you understand this and practice safe sex, even if your partner also has HIV, by using a latex condom or other barrier method. This medicine will also not keep you from giving HIV to other people if they are exposed to your blood. Do not re-use or share needles with anyone.

Birth control pills may not work as well while you are using efavirenz. Use another form of birth control while you are taking this medicine and for 12 weeks after stopping it to keep from getting pregnant. Other forms include condoms, a diaphragm, or a contraceptive foam or jelly.

Check with your doctor right away if you develop a skin rash; blistering, peeling, or loosening of the skin; red skin lesions; sores or ulcers on the skin; or fever or chills while you are using this medicine.

Tell the doctor in charge that you are taking this medicine before you have any medical tests. The results of some tests may be affected by this medicine.

Sustiva Side Effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common
  • Depression
  • skin rash or itching
Less common
  • Blood in the urine
  • difficult or painful urination
  • pain in the lower back or side
  • Abdominal or stomach pain
  • blistering
  • changes in vision
  • clumsiness or unsteadiness
  • confusion
  • convulsions (seizures)
  • cough
  • dark urine
  • delusions
  • double vision
  • fainting
  • fast or pounding heartbeat
  • fever or chills
  • headache (severe and throbbing)
  • hives
  • inappropriate behavior
  • loss of appetite
  • mood or mental changes (severe)
  • muscle cramps or pain
  • nausea or vomiting
  • nerve pain
  • open sores
  • pain, tenderness, bluish color, or swelling of the leg or foot
  • rapid weight gain
  • seeing, hearing, or feeling things that are not there
  • sense of constant movement of self or surroundings
  • sores, ulcers, or white spots in the mouth or on the lips
  • speech disorder
  • swelling or tenderness in the upper abdominal or stomach area
  • swelling of the hands, arms, feet, or legs
  • thoughts of suicide or attempts at suicide
  • tightness in the chest
  • tingling, burning, numbness, or pain in the hands, arms, feet, or legs
  • tingling, burning, or prickling sensations
  • tremor
  • troubled breathing
  • unusual tiredness
  • weight loss
  • wheezing
  • yellow eyes or skin
Incidence not known
  • Actions that are out of control
  • attack, assault, or force
  • continuing vomiting
  • delusions of persecution, mistrust, suspiciousness, or combativeness
  • difficult or labored breathing
  • early appearance of redness or swelling of the skin
  • general feeling of tiredness or weakness
  • irritability
  • late appearance of rash with or without weeping blisters that become crusted, especially in sun-exposed areas of the skin, may extend to unexposed areas
  • light-colored stools
  • nervousness
  • shortness of breath
  • talking, feeling, and acting with excitement

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common
  • Diarrhea
  • dizziness
  • drowsiness
  • headache
  • increased sweating
  • poor concentration
  • trouble with sleeping
Less common or rare
  • Abnormally decreased sensitivity, particularly to touch
  • agitation or anxiety
  • belching
  • change in sense of taste or smell
  • dry mouth
  • excessive gas
  • false sense of well-being
  • flaking and falling off of the skin
  • flushing
  • general feeling of discomfort
  • heartburn
  • indigestion
  • joint pain
  • lack of feeling or emotion
  • loss of hair
  • loss of memory
  • loss of sense of reality
  • mood changes
  • pain
  • painful, red, hot, or irritated hair follicles
  • ringing in the ears
  • stomach discomfort
  • unusual dreams
  • weakness
Incidence not known
  • Difficulty having a bowel movement (stool)
  • discoloration of the fingernails or toenails
  • increased amount of fat in the upper back and neck, or around the chest and stomach area
  • lose fat from the legs, arms, and face
  • swelling of the breasts or breast soreness in both females and males

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

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  • Sustiva Prescribing Information (FDA)
  • Sustiva Consumer Overview
  • Sustiva Detailed Consumer Information (PDR)
  • Sustiva MedFacts Consumer Leaflet (Wolters Kluwer)
  • Efavirenz Professional Patient Advice (Wolters Kluwer)