Ritonavir (patient information)

IMPORTANT WARNING:
Serious or potentially life-threatening reactions can occur when ritonavir is taken along with certain drugs. Therefore, do not take ritonavir with alprazolam (Xanax); amiodarone (Cordarone); astemizole (Hismanal); belladonna, phenobarbital, and ergotamine tartrate (Bellergal-S, Bel-Phen-Ergot S, Phenerbel-S); bepridil (Vascor); bromocriptine (Parlodel); bupropion (Wellbutrin); cabergoline (Dostinex); cisapride (Propulsid); clorazepate (Tranxene); clozapine (Clozaril); diazepam (Valium); dihydroergotamine (D.H.E. 45, Migranal); disopyramide (Norpace); encainide (Enkaid); ergoloid mesylates (Germinal, Hydergine); ergonovine (Ergotrate Maleate); ergotamine (Cafatine, Cafergot, Cafetrate, others); estazolam (ProSom); flecainide (Tambocor); fluoxetine (Prozac, Sarafem); flurazepam (Dalmane); meperidine (Demerol); methylergonovine (Methergine); methysergide (Sansert); mexiletine (Mexitil); midazolam (Versed); nefazadone (Serzone); pergolide (Permax); pimozide (Orap); piroxicam (Feldene); propafenone (Rythmol); propoxyphene (Darvon); quinidine; rifabutin (Mycobutin); terfenadine (Seldane); triazolam (Halcion); or zolpidem (Ambien).

Why is this medication prescribed
Ritonavir is used to treat human immunodeficiency virus (HIV) infection. It belongs to a class of drugs called protease (pro' tee ace) inhibitors, which slow the spread of HIV infection in the body. It is usually taken with other antiviral medications. Ritonavir is not a cure and may not decrease the number of HIV-related illnesses. Ritonavir does not prevent the spread of HIV to other people.

This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

How should this medicine be used
Ritonavir comes as a capsule and liquid to take by mouth. It is usually taken every 12 hours (twice a day). Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take ritonavir exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Mix just one dose at a time and take the whole dose within 1 hour of mixing. Rinse the cup after each dose.

Continue to take ritonavir even if you feel well. Do not stop taking ritonavir without talking to your doctor.

What special precautions should I follow
Before taking ritonavir:


 * tell your doctor and pharmacist if you are allergic to ritonavir or any other drugs.
 * in addition to the drugs listed in the IMPORTANT WARNING section, also tell your doctor and pharmacist what other prescription and nonprescription medications you are taking, especially anticoagulants ('blood thinners') such as warfarin (Coumadin), cholesterol-lowering medications such as lovastatin (Mevacor) and simvastatin (Zocor), clarithromycin (Biaxin), desipramine (Norpramin), didanosine (Videx), disulfiram (Antabuse), heart medications, indinavir (Crixivan), ketoconazole (Nizoral), medications for depression and seizures, medications that suppress the immune system such as cyclosporine (Neoral, Sandimmune) and tacrolimus (Prograf), meperidine (Demerol), Methadone (Dolobid), metronidazole (Flagyl), oral contraceptives (birth control pills), pain relievers, rifabutin (Mycobutin), rifampin (Rifadin, Rimactane), saquinavir (Invirase), sildenafil (Viagra), theophylline (Theo-Dur), vitamins, and nutritional supplements.
 * tell your doctor and pharmacist what herbal products you are taking, especially St. John's wort and products containing St. John's wort.
 * tell your doctor if you have or have ever had liver disease, diabetes, hemophilia, or a history of alcohol abuse.
 * tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking ritonavir, call your doctor immediately.
 * tell your doctor if you drink alcohol.

What special dietary instructions should I follow
Take ritonavir with food. Ritonavir liquid may be taken alone or mixed with chocolate milk or the food supplements Ensure or Advera. Do not mix it with any other fluids.

What should I do if I forget a dose
Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

Mild side effects
''Side effects from ritonavir are common. Tell your doctor if any of these symptoms are severe or do not go away:''


 * loss of strength or weakness
 * upset stomach
 * vomiting
 * diarrhea or loose stools
 * headache
 * dizziness
 * shift in body fat

Severe side effects
If you experience any of the following symptoms, call your doctor immediately:


 * rash
 * hives
 * difficulty breathing
 * swelling of the tongue or lips
 * tingling sensation or numbness in the hands, feet, or around the lips
 * excessive tiredness
 * lack of energy
 * loss of appetite
 * pain in the upper right part of the stomach
 * yellowing of the skin or eyes

''Ritonavir may increase the sugar level in your blood. If you experience any of the following symptoms, call your doctor immediately:''


 * frequent urination
 * increased thirst
 * weakness
 * dizziness
 * headache

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/MedWatch/report.htm] or by phone [1-800-332-1088].

What storage conditions are needed for this medicine
Keep this medication in the container it came in, tightly closed, and out of reach of children. Keep retonavir capsules and liquid in the refrigerator; do not freeze. The liquid bottle in use can be stored in a cool area for up to 30 days. Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

In case of emergency/overdose
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

What other information should I know
Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to ritonavir.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

Brand names

 * Norvir®
 * Norvir® Softgel