In the U.S.—

• Antiviral, systemic

Atazanavir (at-a-za-NA-veer) 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).

Atazanavir 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 usually related to AIDS or HIV disease. Atazanavir will not keep you from spreading HIV to other people. People who receive this medicine may continue to have other problems usually related to AIDS or HIV disease.

This medicine is available only with your doctor's prescription, in the following dosage forms:

Oral
• Capsules (U.S.)

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 atazanavir, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to atazanavir. Also tell your doctor and pharmacist if you are allergic to any other substances, such as [foods, preservatives, or dyes].

Pregnancy—Atazanavir did not cause birth defects in animal studies. However, in animal studies, atazanavir has been found to cause reduced weight and delayed growth in the infants. Atazanavir has not been studied in pregnant women.

Breast-feeding—It is not known whether atazanavir passes into breast milk. However, breast-feeding is usually not recommended in AIDS patients because of the risk of passing the AIDS virus on to the infant.

Children—Studies on this medicine have been done only in adult patients, and there is limited recommendations comparing the use of atazanavir in children with use in other age groups. Atazanavir should not be administered to children under the age of 3 months.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults. There is no specific information comparing use of atazanavir in the elderly with use in other age groups.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your health care professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine. When you are taking atazanavir, it is especially important that your doctor and pharmacist know if you are taking any of the following:

• Amiodarone (e.g., Cordarone) or
• Atorvastatin (e.g., Lipitor) or
• Clarithromycin (e.g., Biaxin) or
• Diltiazem (e.g., Cardizem) or
• Felodipine (e.g., Plendil) or
• Lidocaine (e.g., Xylocaine) or
• Nicardipine (e.g., Cardene) or
• Nifedipine (e.g., Adalat, Procardia) or
• Oral contraceptives (“birth control pills”) containing ethinyl estradiol and norethindrone (e.g., Brevicon, Loestrin, Modicon, Ortho-Novum) or
• Quinidine (e.g., Cardioquin, Quinidex Extentabs) or
• Rifabutin (e.g., Mycobutin) or
• Saquinavir (e.g., Fortovase, Invirase) or
• Sildenafil (e.g., Viagra) or
• Tadalafil (e.g., Cialis)
• Tricyclic antidepressants (medicine for depression) or
• Vardenafil (e.g. Levitra)
• Verapamil (e.g., Calan, Isoptin) or
• Warfarin (e.g., Coumadin)—Use of atazanavir with these medicines may increase the amount of these medicines in your body and increase your chance of getting side effects from these medicines.

• Antiacids or
• Buffered medicines—Atazanavir should be taken two hours before or one hour after taking these medicines.

• Bepridil (e.g., Vascor) or
• Cisapride (e.g., Propulsid) or
• Dihydroergotamine (e.g., D.H.E. 45 injection, Migranal nasal spray) or
• Ergonovine (e.g., Ergotrate injection) or
• Ergotamine containing products (e.g., Bellergal, Bellaspas, Cafergot, Wigraine) or
• Indinavir (e.g., Crixivan) or
• Irinotecan (e.g., Camptosar) or
• Lovastatin (e.g., Mevacor ) or
• Methylergonovine (e.g., Methergine) or
• Midazolam (e.g., Versed) or
• Pimozide (e.g., Orap) or
• Proton pump inhibitors (esomeprazole [e.g., Nexium], lansoprazole [e.g., Prevacid], omeprazole [e.g., Prilosec], pantoprazole [e.g., Protonix], rabeprazole [e.g., Aciphex]) or
• Rifampin (e.g., Rifadin) or
• Simvastatin (e.g., Zocor) or
• St. John's wort (Hypericum perforatum) or
• Triazolam (e.g., Halcion )—These medicines should not be taken with atazanavir because they increase your chance of getting serious side effects.

• Didanosine (e.g., Videx)—Atazanavir should be taken at different time than didanosine so that both will be absorbed from the stomach.

• Efavirenz (e.g., Sustiva)—Use of this medicine with atazanavir may decrease the amount of atazanavir in the body and make your HIV worse.
• H₂-Receptor antagonists (cimetidine [e.g., Tagamet], famotidine [e.g., Pepcid], nizatidine [e.g., Axid], ranitidine [e.g., Zantac]) or

• Ritonavir (e.g., Norvir)—Use of this medicine with atazanavir may increase the amount of atazanavir in the body and increase your chance of getting side effects from atazanavir.

• Diabetes mellitus (sugar diabetes) or
• Hyperglycemia—Atazanavir may increase or decrease the amount of sugar in your blood, dose adjustments of insulin or other medicines for diabetes may be needed. Talk to your doctor about this.

• Heart conduction problems, preexisting—Atazanavir may change the way your heart beats and increase your chance of getting side effects.

• Hemophilia, type A and B—Use of atazanavir may increase your chance of having serious bleeding problems.

• Hepatitis, or
• Transaminase, elevated—Use of atazanavir may make these problems worse.

• Liver disease—May increase your chance of getting side effects.

It is important that atazanavir be taken with food.

Dosing—

The dose of atazanavir may 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 atazanavir. If your dose is different, do not change it unless your doctor tells you to do so.

The number of capsules that you take depends on the strength of the medicine.

• For oral dosage form (capsules):
  • For treatment of HIV infection:
    • Adults—300 to 400 mg once daily with food
    • Children (3 months and older)—Use and dose must be determined by your doctor.

Missed dose—

If you miss a dose of this medicine, take it as soon as you remember. However, if it is within 6 hours of your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage—

To store this medicine:

• Keep out of the reach of children.
• Do not store in the bathroom, near the kitchen sink, or in other damp places. heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Ask your health care professional how you should dispose of any medicine you do not use. Be sure that any discarded medicine is out of the reach of children.

Do not take any other medicines without checking with your doctor first. To do so may increase the chance of side effects from atazanavir.

It is very important that your doctor check your progress at regular visits to make sure this medicine is working properly and to check for unwanted 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:

• Incidence not determined
  • Abdominal discomfort;  blurred vision ;  chills;  decreased appetite ;  diarrhea;  dizziness or lightheadedness;  dry mouth;  fast, shallow breathing;  fatigue;  fever;  flushed, dry skin;  fruit-like breath odor;  general feeling of discomfort ;  hives;  increased hunger ;  increased thirst;  increased urination;  itching;  loss of consciousness;  muscle pain or cramping;  nausea;  shortness of breath;  skin rash;  sleepiness;  stomachache;  sweating;  tightness in chest;  trouble in breathing ;  unexplained weight loss;  unusual tiredness or weakness;  vomiting;  wheezing;  yellow eyes or skin 
  
  

• Symptoms of Overdose

  Get emergency help immediately if any of the following symptoms of overdose occur

  • Abdominal or stomach pain;  area rash ;  chills;  clay-colored stools ;  dark urine; dizziness;  dizziness or lightheadedness;  fever;  headache;  itching;  loss of appetite;  nausea;  unpleasant breath odor;  unusual tiredness or weakness ;  vomiting of blood;  yellow eyes or skin 
  
  

Other 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. However, check with your doctor if any of the following side effects continue or are bothersome.

• More Common
  • Back pain;  cough, increased;  discouragement;  feeling sad or empty ;  headache;  irritability ;  lack of appetite;  loss of interest or pleasure;  redistribution or accumulation of body fat;  trouble concentrating;  trouble sleeping 
  
  

• Less common
  • Burning, numbness, tingling, or painful sensations;  difficulty in moving;  muscle stiffness ;  pain;  pain in joints;  sleeplessness;  unable to sleep;  unsteadiness or awkwardness;  weakness in arms, hands, legs, or feet 
  
  

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