Generic name: Ritonavir.

Norvir is a protease inhibitor. It blocks the protease enzyme vital to the final stages of human immunodeficiency virus (HIV) replication, reducing the amount of virus available to infect new cells. 

Quick Facts About Norvir


Used in combination with other drugs called nucleoside analogues (such as Retrovir or Hivid) to treat advanced HIV infection in selected patients. HIV causes the immune system to break down so that it can no longer fight off infections. It can lead to the fatal disease known as acquired immune deficiency syndrome (AIDS). Does not cure HIV infection.

Norvir Dosage

Take with meals to allow medication to be absorbed properly by the body. If taking oral solution, improve taste of medication by mixing with chocolate milk or a liquid nutritional product within 1 hour of taking dose; measure amount of liquid carefully with measuring cup or spoon to assure accurate dosage. Take exactly as prescribed, at even intervals. Do not discontinue use without consulting your doctor.

  • Usual adult dose: 600 milligrams taken twice per day (every 12 hours). Inform your doctor if you experience nausea initially; he or she may lower dosage and increase it gradually.
  • Usual child dose: not prescribed for children.
  • Missed dose: take as soon as possible, unless almost time for next dose. In that case, do not take missed dose; go back to regular schedule. Do not double doses.

Norvir Side Effects

Overdose symptoms:

none reported. However, if you suspect an overdose, immediately seek medical attention.

More common side effects: appetite changes, constipation, headache, nausea, numbness around face or mouth, stomach pain, vomiting, weakness.

Less common Norvir side effects: diarrhea, dizziness, drowsiness, fever, gas, general feeling of illness, irritated throat, muscle pain, rash, taste changes. Rare side effects: disturbed thoughts, insomnia, “pins and needles” sensation in arms and legs, sweating.


Combining Norvir with certain medications could cause serious, life-threatening effects.

Do not combine Norvir with:

amiodarone (Cordarone), astemizole (Hismanal), bepridil (Vascor), bupropion (Wellbutrin), cisapride (Propulsid), clozapine (Clozaril), encainide (Enkaid), flecainide (Tambocor), meperidine (Demerol), piroxicam (Feldene), propafenone (Rythmol), propoxyphene (Darvon), quinidine (Quinaglute or Quinidex), rifabutin (Mycobutin), or terfenadine (Seldane). Norvir may increase effect of certain sedatives and sleeping medications, causing extreme sedation and breathing difficulties. Do not combine with: alprazolam (Xanax), dorazepate (Tranxene), diazepam (Valium), estazolam (ProSom), flurazepam (Dalmane), midazolam (Versed), triazolam (Halcion), or zolpidem (Ambien). Inform your doctor before combining Norvir with: calcium channel blockers such as amlodipine (Norvasc), diltiazem (Cardizem, Dilacor XR), felodipine (Plendil), isradipine (DynaCirc), nicardipine (Cardene), nisoldipine (Sular), or verapamil (Calan, Isoptin, or Verelan); clonodine (Catapres); desipramine (Norpramin); disulfiram (Antabuse); enzyme inducers such as carbamazepine (Tegretol), phenobarbital (Donnatal), phenytoin (Dilantin), or rifampin (Rifadin or Rimactane); enzyme inhibitors such as clarithromycin (Baxin), or isoniazid (Nydrazid); metronidazole (such as Flagyl or Metrogel); oral contraceptives; saquinavir (Invirase); theophylline (Theo-Dur or Uniphyl).

Tobacco decreases the effects of Norvir; do not use while taking medication. Use antacids with caution. 

Special Cautions

If pregnant or planning to become pregnant, inform your doctor immediately. Do not breastfeed; HIV appears in breast milk and could affect a nursing infant

No special precautions apply to seniors.

Not generally prescribed for children under 16 years.

  • Long-term effects of medication still are not known. Since the HIV virus remains in the body, risk is still present for complications including opportunistic infections such as pneumonia, tuberculosis, and fungal infection. It is important to remain under the care of a doctor and go to follow-up appointments.
  • Many medications could be dangerous or life-threatening if taken with Norvir. Read “Interactions” section carefully.
  • Inform your doctor before treatment if you have liver disease (especially cirrhosis) or kidney disease.
  • Does not reduce risk of transmitting HIV to others through sexual contact or blood contamination. Always use condoms and never share needles or equipment for injections with other people.
  • Capsules should be refrigerated and protected from light. Oral solution best kept in refrigerator. Avoid exposure to heat and keep tightly closed in original container.

Note: provides accurate and independent information prescription pills, over-the-counter medicines and natural products. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment. If you have questions about  dosage, or Norvir side effects, please contact your healthcare provider