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Other drug names: A-Am An-Az B C-Ch Ci-Cz D-Dh Di-Dz E F G H I-J K-L M-Mh Mi-Mz N-Nh Ni-Nz O P-Pl Pm-Pz Q-R S-Sn So-Sz T-To Tp-Tz U-V W-Z 0-9   

Ritonavir (Systemic)

Brand Names

In the U.S.-

  • Norvir

In Canada-

  • Norvir
  • Norvir SEC


  • Antiviral, systemic


Ritonavir ( rit-ON-uh-veer) is used, alone or in combination 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).

Ritonavir 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. Ritonavir 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:

  • Capsules (U.S. and Canada)
  • Oral solution (U.S. and Canada)

Before Using This Medicine

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 ritonavir, the following should be considered:

Allergies- Tell your doctor if you have ever had any unusual or allergic reaction to ritonavir. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy- Studies have not been done in humans. However, in animal studies, ritonavir has been found to cause reduced weight and delayed growth in the infants. Ritonavir did not cause birth defects in animal studies.

Breast-feeding- It is not known whether ritonavir 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- This medicine has been tested in a limited number of children 2 years of age and older. In effective doses, the medicine has not been shown to cause different side effects or problems than it does in adults.

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 ritonavir 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 taking ritonavir, it is especially important that your health care professional know if you are taking any of the following:

  • Amiodarone (e.g., Cordarone) or
  • 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
  • Flecainide (e.g., Tambocor) or
  • Lovastatin (e.g., Mevacor) or
  • Methylergonovine (e.g., Methergine) or
  • Midazolam (e.g., Versed) or
  • Pimozide (e.g., Orap) or
  • Propafenone (e.g., Rythmol) or
  • Quinidine (e.g., Quinidex) or
  • Simvastatin (e.g., Zocor) or
  • St. John's wort (hypericum perforatum) or
  • Triazolam (e.g., Halcion)-Do not take any of these medicines with ritonavir
  • Clarithromycin (e.g., Biaxin) or
  • Desipramine (e.g., Norpramin) or
  • Didanosine (e.g., Videx) or
  • Disulfiram (e.g., Antabuse) or
  • Ethinyl estradiol-containing birth control pills progestin only or ****Ĺ“mini pills" (e.g., Nor-QD, Micronor, Ovrette) or
  • Indinavir (e.g., Crixivan) or
  • Ketoconazole (e.g., Nizoral) or
  • Meperidine (e.g., Demerol) or
  • Methadone (e.g., Dolophine) or
  • Metronidazole (e.g., Flagyl) or
  • Rifabutin (e.g., Mycobutin) or
  • Rifampin (e.g., Rifadin) or
  • Saquinavir (e.g., Fortovase, Invirase) or
  • Sildenafil (e.g., Viagra) or
  • Theophylline (e.g., Theo-Dur, Theochron)-A change in amount or how often you take these medications may be needed.

Other medical problems- The presence of other medical problems may affect the use of ritonavir. Make sure you tell your doctor if you have any other medical problems, especially:
  • Diabetes mellitus (sugar diabetes)-Ritonavir may increase the amount of sugar in your blood.
  • Hemophilia-Possible increased risk of bleeding
  • Liver disease or other liver problems-Effects of ritonavir may be increased because of slower removal from the body

Proper Use of This Medicine

It is important that ritonavir be be taken with food .

For patients taking the solution (liquid) form of this medicine:

  • Shake the bottle well before using.
  • Use a specially marked measuring syringe to measure each dose accurately. The average household teaspoon may not hold the right amount of liquid.

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.

Keep taking ritonavir for the full time of treatment , even if you begin to feel better.

This medicine works best when there is a constant amount in the blood. To help keep the amount constant, do not miss any doses. Also, it is best to take the doses at evenly spaced times, day and night . For example, if you are to take two doses a day, the doses should be spaced about 12 hours apart. If you need help in planning the best times to take your medicine, check with your health care professional.

Only take medicine that your doctor has prescribed specially for you. Do not share your medicine with others.


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

  • For oral dosage form (capsules):
    • For treatment of HIV infection:
      • Adults-600 milligrams (mg) two times a day.
      • Children-This oral dosage form is usually not used for children. Please refer to oral solution dosage form.
  • For oral dosage form (oral solution):
    • For treatment of HIV infection:
      • Adults-600 milligrams (mg) two times a day.
      • Children 2 years of age and older-Dose is based on body size and must be determined by your doctor.
      • Children less than 2 years of age-Use and dose must be determined by your doctor.
Ritonavir can be used in combination with other medicines. Check with your doctor for more information on these doses.

Missed dose-

If you miss a dose of this medicine, take it as soon as you remember. 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.


To store this medicine:

  • Keep out of the reach of children.
  • Store the capsule form of this medicine in the refrigerator. The oral solution form should not be refrigerated; it should be stored at room temperature.
  • 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. Be sure that any discarded medicine is out of the reach of children.

Precautions While Using This Medicine

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

It is very important that your doctor check your progress at regular visits to make sure this medicine is working properly and check for unwanted effects, especially increases in blood sugar.

This medicine may decrease the effects of some oral contraceptives (birth control pills). To avoid unwanted pregnancy, it is a good idea to use some additional contraceptive measures while being treated with ritonavir .

Side Effects of This Medicine

Side Effects of This Medicine

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 as soon as possible if any of the following side effects occur:

  • Less common
    • Fainting;  feeling faint, dizzy, or light-headedness ;  feeling of warmth or heat;  flushing or redness of skin especially on face and neck;  headache;  sweating 

  • Rare
    • Confusion;  dehydration;  dry or itchy skin;  fatigue;  fruity mouth odor;  increased hunger ;  increased thirst;  increased urination;  nausea;  vomiting ;  weight loss 

  • Not Known
    • bloating;  chills;  constipation;  cough;  darkened urine;  difficulty breathing;  fast heartbeat;  fever;  hives or welts;  indigestion;  itching;  large, hive-like swelling on face, eyelids, lips, tongue, throat, hands, legs, feet, sex organs;  loss of appetite;  noisy breathing;  pains in stomach, side, or abdomen, possibly radiating to the back;  redness of skin;  shortness of breath ;  skin rash;  tightness in chest;  wheezing;  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
    • Abdominal pain;  acid or sour stomach ;  belching;  burning, crawling, itching, numbness, prickling, pins and needles, or tingling feelings;  Change in sense of taste;  diarrhea;  dizziness;  heartburn;  sleepiness or unusual drowsiness;  sleeplessness;  trouble sleeping;  unable to sleep;  weakness 

  • Less common
    • Bloated, full feeling;  body aches or pain;  congestion;  delusions ;  dementia;  difficulty in moving;  discouragement;  dryness or soreness of throat;  excess air or gas in stomach or intestines;  fear;  feeling sad or empty;  general feeling of discomfort or illness;  hoarseness;  increased urge to urinate during the night;  irritability ;  lack of appetite;  loss of interest or pleasure;  mood or mental changes;  muscle pain or stiffness;  nervousness ;  pain in joints or in unspecified location;  passing gas;  runny nose;  tender, swollen glands in neck;  throat irritation;  tiredness;  trouble concentrating;  trouble in swallowing;  voice changes;  waking to urinate at night 

  • Not Known
    • increased fat deposits on face, neck, and trunk 

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

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Last updated: Tue, 06 Jan 2009 00:20:03 GMT