Atazanavir is an antiviral medication in a group of HIV medicines called protease (PRO-tee-ayz) inhibitors. Atazanavir prevents human immunodeficiency virus (HIV) cells from multiplying in your body.

Atazanavir is used to treat HIV, which causes acquired immunodeficiency syndrome (AIDS). Atazanavir is not a cure for HIV or AIDS.

Atazanavir may also be used for purposes not listed in this medication guide.

You should not take this medication if you are allergic to atazanavir.

There are many other drugs that should not be used together with atazanavir. Tell your doctor about all other medicines you use. Do not start a new medication without telling your doctor. Keep a list of all your medicines and show it to any healthcare provider who treats you.

Before using atazanavir, tell your doctor if you have liver disease, hepatitis, kidney disease (or if you are on dialysis), diabetes, a bleeding disorder, high cholesterol, a bleeding disorder, heart problems, or if you have ever used a protease inhibitor in the past.

Taking this medication will not prevent you from passing HIV to other people. Avoid having unprotected sex or sharing razors or toothbrushes. Sharing drug or medicine needles is never safe, even for a healthy person.

You should not use atazanavir if you are allergic to it.

There are many other drugs that can cause serious or life-threatening medical problems if you take them together with atazanavir. The following drugs should not be used while you are taking atazanavir:

• alfuzosin (Uroxatral);

• cisapride (Propulsid);

• ergot medicine such as ergotamine (Ergomar, Cafergot, Migergot), dihydroergotamine (D.H.E. 45, Migranal), ergonovine (Ergotrate), or methylergonovine (Methergine);

• indinavir (Crixivan);

• irinotecan (Camptosar);

• lovastatin (Advicor, Altoprev, Mevacor) or simvastatin (Simcor, Zocor)

• oral midazolam (Versed)

• nevirapine (Viramune);

• pimozide (Orap);

• rifampin (Rifadin, Rimactane, Rifater);

• sildenafil (Revatio, for treating pulmonary arterial hypertension);

• St. John's wort; or

• triazolam (Halcion).

To make sure you can safely take atazanavir, tell your doctor if you have any of these other conditions:

• liver disease, including hepatitis B or C;

• kidney disease (or if you are on dialysis);

• diabetes;

• a bleeding disorder such as hemophilia;

• high cholesterol or triglycerides;

• a heart rhythm disorder, a heart condition called "AV block"; or

• if you have ever used a protease inhibitor in the past.

FDA pregnancy category B. This medication is not expected to be harmful to an unborn baby, but HIV can be passed to your baby if you are not properly treated during pregnancy. Take all of your HIV medicines as directed to control your infection. Atazanavir must be given together with ritonavir during pregnancy and for a short time after childbirth. Follow your doctor's dosing instructions very carefully.

Atazanavir can make birth control pills, patches, injections, or vaginal rings less effective. Ask your doctor about using a non hormone method of birth control (such as a condom, diaphragm, spermicide) to prevent pregnancy while taking atazanavir.

Women with HIV or AIDS should not breast-feed a baby. Even if your baby is born without HIV, the virus may be passed to the baby in your breast milk.

Do not give this medication to a child younger than 6 years old. Do not give atazanavir alone (without ritonavir) to a child younger than 13 years old, or to a child who weighs less than 88 pounds.