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AIDSinfo Drug Database

AIDSinfo Drug Database

Drugs by class



Atazanavir  Audio icon

Brand Name: Reyataz
Other Names: ATV, atazanavir sulfate
Drug Class: Protease Inhibitors
Approved Use: Treatment of HIV Infection

Drug Image:
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Reyataz 300mg
Atazanavir 150
Atazanavir 200
Chemical Image:
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atazanavir sulfate
atazanavir sulfate
Molecular Weight: 802.942


Atazanavir can cause serious, life-threatening side effects. These include heart rhythm problems, severe rash, liver problems, and life-threatening drug interactions.

Contact your health care provider right away if you have any of the following symptoms that could be signs of heart rhythm problems:

  • Dizziness.
  • Lightheadedness.

Stop taking atazanavir and contact your health care provider right away if you have a severe rash or a rash combined with any of the following symptoms:

  • General ill feeling or “flu-like” symptoms.
  • Fever.
  • Muscle or joint aches.
  • Red or inflamed eyes, like “pink eye” (conjunctivitis).
  • Blisters.
  • Mouth sores.
  • Swelling of the face.
  • Painful, warm, or red lump under your skin.

In people with existing liver problems, including infection with hepatitis B virus (HBV) or hepatitis C virus (HCV), atazanavir can cause worsening of liver problems. Contact your health care provider right away if you have any of the following symptoms that could be signs of liver problems:

  • Yellowing of your skin or the whites of your eyes (jaundice).
  • Dark-colored urine.
  • Light-colored bowel movements.
  • Nausea.
  • Itching.
  • Pain in the stomach area (abdominal pain).
While taking atazanavir, it is important to keep all of your appointments with your health care provider. 

What is atazanavir?

Atazanavir is a prescription medicine approved by the U.S. Food and Drug Administration (FDA) for the treatment of HIV infection in adults and children 3 months of age and older who weigh at least 11 pounds (5 kg). Atazanavir is always used in combination with other HIV medicines.

Atazanavir belongs to a class (group) of HIV medicines called protease inhibitors (PIs). PIs block an HIV enzyme called protease. (An enzyme is a protein that starts or increases the speed of a chemical reaction.) By blocking protease, PIs prevent HIV from multiplying and can reduce the amount of HIV in the body.

HIV medicines can’t cure HIV/AIDS, but taking a combination of HIV medicines (called an HIV regimen) every day helps people with HIV live longer, healthier lives. HIV medicines also reduce the risk of HIV transmission.

What should I tell my health care provider before taking atazanavir?

Before taking atazanavir, tell your health care provider:

  • If you are allergic to atazanavir or any other medicines.
  • If you have heart problems.
  • If you have liver problems, including HBV or HCV infection.
  • If you have phenylketonuria (PKU). Atazanavir oral powder includes an artificial sweetener (aspartame) that contains phenylalanine. Phenylalanine may be harmful to people with PKU. 
  • If you are receiving kidney dialysis treatment.
  • If you have diabetes.
  • If you have hemophilia.
  • If you have any other medical conditions.
  • If you are pregnant or plan to become pregnant. Whether atazanavir can harm an unborn baby is unknown. Atazanavir should be used during pregnancy only if clearly needed. Some pregnant women have experienced serious side effects when taking atazanavir with certain other HIV medicines. Talk to your health care provider about possible risks with taking atazanavir when pregnant.
  • If you are breastfeeding or plan to breastfeed. Do not breastfeed if you are infected with HIV or are taking atazanavir.
  • If you are using hormone-based birth control (such as birth control pills, injections, vaginal rings or implants, or a contraceptive patch). Atazanavir may make these forms of birth control less effective. Your health care provider can help you decide how to adjust your birth control while you are taking atazanavir.
  • About other prescription and nonprescription medicines, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Atazanavir may affect the way other medicines or products work, and other medicines and products may affect how atazanavir works. Taking atazanavir together with certain medicines or products may cause serious, life-threatening side effects.

How should I take atazanavir?

Atazanavir (brand name: Reyataz) comes in the following forms and strengths:

  • 150-mg, 200-mg, and 300-mg capsules.
  • Oral powder (50 mg of atazanavir per packet).

Atazanavir capsules are for use in adults and in children 6 years of age and older. Atazanavir oral powder must be taken with ritonavir and is for use in children 3 months of age and older who weigh at least 11 pounds (5 kg).

Take atazanavir according to your health care provider’s instructions.

Take atazanavir with food. Swallow the capsules whole. Do not open the capsules.

Atazanavir oral powder must be mixed with food or liquid. When preparing the oral powder for a child who can take food, mix the oral powder with food such as applesauce or yogurt, instead of a liquid (milk, infant formula, or water). If atazanavir oral powder is mixed with water, your child must eat food right after taking the oral powder. For infants less than 6 months old and who cannot eat solid food or drink from a cup, first mix the oral powder with infant formula. Then use an oral dosing syringe to give the oral powder and formula mixture to the infant. (Ask your pharmacist for a dosing syringe.) For more information about mixing atazanavir oral powder, see the Patient Information leaflet that comes with atazanavir.

Always take atazanavir in combination with other HIV medicines.

If you take too much atazanavir, contact your health care provider or local poison control center (1-800-222-1222) right away, or go to the nearest hospital emergency room.

For more information on how to take atazanavir, see the FDA drug label from DailyMed. (DailyMed is a federal website that includes the most recent drug labels submitted to FDA.)

What should I do if I forget a dose?

If you miss a dose of atazanavir, take the missed dose as soon as you remember it. But if it is almost time for your next scheduled dose, skip the missed dose and just take your next dose at the regular time. Do not take two doses at the same time to make up for a missed dose.

What side effects can atazanavir cause?

Atazanavir may cause side effects. Most side effects from atazanavir are manageable, but a few can be serious. Serious side effects of atazanavir include heart rhythm problems, severe rash, liver problems, and life-threatening drug interactions. (See the WARNING above.)

Other possible side effects of atazanavir include:

  • Mild rash (redness and itching).
  • Yellowing of your skin or the whites of your eyes (jaundice), caused by increases in bilirubin levels in your blood. Contact your health care provider right away if you have this side effect.
  • Some people taking atazanavir have had liver problems. People with a history of HBV or HCV infection or who have elevated results on liver function tests may have an increased risk of developing new or worsening liver problems while taking atazanavir. Liver function tests may be done before and during treatment with atazanavir.
  • Diabetes and high blood sugar (hyperglycemia).
  • Changes in body fat (including gain or loss of fat).
  • Immune reconstitution inflammatory syndrome (IRIS), a condition that sometimes occurs when the immune system begins to recover after treatment with an HIV medicine. As the immune system gets stronger, it may have an increased response to a previously hidden infection.
  • Increased bleeding problems in people with hemophilia.
  • Gallbladder problems. Contact your health care provider right away if you develop symptoms of gallbladder problems (pain in your right or middle upper stomach area, fever, nausea and vomiting, or yellowing of your skin or the whites of your eyes [jaundice]).
  • Kidney stones. Contact your health care provider if you have pain in your low back or low stomach area, blood in your urine, or pain when urinating.

Tell your health care provider if you have any side effect that bothers you or that does not go away.

These are not all the possible side effects of atazanavir. To learn more about possible side effects of atazanavir, read the drug label or package insert or talk to your health care provider or pharmacist.

The AIDSinfo fact sheet on HIV Medicines and Side Effects also includes information that may apply to atazanavir.

You can also report side effects to FDA at 1-800-FDA-1088 (1-800-332-1088) or online at

How should atazanavir be stored?

  • Store atazanavir capsules at room temperature, 68°F to 77°F (20°C to 25°C).
  • Keep atazanavir capsules in the container that they came in and keep the container tightly closed.
  • Keep atazanavir oral powder below 86°F (30°C).
  • After atazanavir oral powder is mixed with food or liquid, it may be kept at room temperature, 68°F to 86°F (20°C to 30°C), for up to 1 hour. Use atazanavir oral powder within 1 hour after mixing with food or liquid. 
  • Store atazanavir oral powder in the original packet. Do not open until ready to use.
  • Do not use atazanavir if the original seal over the bottle opening or carton is broken or missing.
  • Throw away atazanavir that is no longer needed or expired (out of date). Follow FDA guidelines on how to safely dispose of unused medicine. 
  • Keep atazanavir and all medicines out of reach of children.

Where can I find more information about atazanavir?

More information about atazanavir is available:

Manufacturer Information

Bristol-Myers Squibb
Main number: 800-332-2056
Patient assistance: 888-281-8981

The above Patient Version drug summary is based on the following FDA label(s): Capsule (gelatin coated), oral powder.

Last Reviewed: June 10, 2016

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