Generic name: Nelfinavir.

Viracept 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 Viracept


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.

Viracept Dosage

Take with meals to allow medication to be absorbed properly by the body. Take exactly as prescribed, at even intervals. Do not discontinue use without consulting your doctor.

  • Usual adult dose: 250 milligrams taken every eight hours around the clock.
  • Usual child dose: for children 14 and over — follow adult dosing schedule. For children 2 to 13 years — 9-13 milligrams per pound of body weight. Not generally recommended for children under 2 years.
  • 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.

Viracept Side Effects

Overdose symptoms:

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

More common side effects: diarrhea, liver inflammation.

Less common Viracept side effects: abdominal pain, gas, nausea, rash, weakness. Rare side effects: allergic reaction, anemia, appetite changes, arthritis, back pain, breathing difficulty, depression, dizziness, emotional instability, eye disorders, fever, general feeling of ill health, headache, irritated or sore throat, itching, kidney stones, low blood platelets, migraine, mouth sores, pancreas inflammation, “pins and needles” in the hands and feet, runny nose, seizure, sexual problems, sleeplessness, sinus irritation, stimulation, stomach bleeding, stomach pain, sweating, vomiting.


Do not combine Viracept with astemizole (Hismanal) or terfenadine (Seldane).

Inform your doctor before combining Viracept with:

AIDS drugs such as lamivudine (Epivir) or zidovudine (AZT); antifungals such as ketoconazole (Nizoral); enzyme inducers such as carbamazepine (Tegretol), phenobarbital (Donnatal), phenytoin (Dilantin), rifabutin (Mycobutin), or rifampin (Rifadin or Rimactane); oral contraceptives; protease inhibitors such as indinavir (Crixican), saquinavir (Invirase), or ritonavir (Norvir).

No known food/other substance interactions.

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 2 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.
  • Inform your doctor before treatment if you have liver disease (especially cirrhosis) or diabetes.
  • 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.
  • Relieve the diarrhea associated with Viracept with loperamide (Imodium), an over-the-counter remedy.

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 Viracept side effects, please contact your healthcare provider