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Last reviewed on RxList: 7/3/2017
Viracept Side Effects Center

Last reviewed on RxList 7/3/2017

Viracept (nelfinavir mesylate) is a type of antiviral medication called a protease inhibitor used to treat HIV, which causes acquired immunodeficiency syndrome (AIDS). Viracept is not a cure for HIV or AIDS. Common side effects of Viracept include diarrhea, nausea, stomach pain, loss of appetite, gas, skin rash, or changes in the shape or location of body fat (especially in your arms, legs, face, neck, breasts, and trunk). Contact your doctor if you experience serous side effects of Viracept including signs of new infection, high blood sugar, rapid heart rate, unusual bleeding, or weakness.

The recommended adult and adolescent dose of Viracept is 1250 mg (five 250 mg tablets or two 625 mg tablets) twice daily or 750 mg (three 250 mg tablets) three times daily. In children 2 to 13 years of age, the recommended dose of Viracept Oral Powder or 250 mg tablets is 45 to 55 mg/kg twice daily or 25 to 35 mg/kg three times daily. Viracept may interact with fluticasone, itraconazole, ketoconazole, lopinavir/ritonavir, methadone, omeprazole, rifabutin, St. John's wort, antidepressants, calcium channel blockers, cholesterol-lowering medicines, drugs that weaken the immune system, insulin or oral diabetes medications, medicines to treat erectile dysfunction, or seizure medications. Tell your doctor all medications and supplements you use. Tell your doctor if you are pregnant before using Viracept. It is unknown if this medication passes into breast milk. Because breast milk can transmit HIV, do not breastfeed.

Our Viracept (nelfinavir mesylate) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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Viracept Consumer Information

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

  • easy bruising, unusual bleeding (nose, mouth, vagina, or rectum), purple or red pinpoint spots under your skin; or
  • high blood sugar--increased thirst, increased urination, hunger, dry mouth, fruity breath odor, drowsiness, dry skin, blurred vision, weight loss.

Nelfinavir may increase your risk of certain infections or autoimmune disorders by changing the way your immune system works. Symptoms may occur weeks or months after you start treatment with nelfinavir. Tell your doctor if you have:

  • signs of a new infection--fever, night sweats, swollen glands, mouth sores, diarrhea, stomach pain, weight loss;
  • chest pain (especially when you breathe), dry cough, wheezing, feeling short of breath;
  • cold sores, sores on your genital or anal area;
  • rapid heart rate, feeling anxious or irritable, weakness or prickly feeling, problems with balance or eye movement;
  • trouble speaking or swallowing, severe lower back pain, loss of bladder or bowel control; or
  • swelling in your neck or throat (enlarged thyroid), menstrual changes, impotence, loss of interest in sex.

Common side effects may include:

  • infections;
  • nausea, diarrhea, gas, stomach pain;
  • loss of appetite;
  • rash; or
  • changes in the shape or location of body fat (especially in your arms, legs, face, neck, breasts, and waist).

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Read the entire detailed patient monograph for Viracept (Nelfinavir Mesylate)


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Viracept Professional Information


Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Clinical Trials Experience: Adults And Adolescents (13 Years and Older)

The safety of VIRACEPT was studied in over 5000 patients who received drug either alone or in combination with nucleoside analogues. The majority of adverse events were of mild intensity. The most frequently reported adverse event among patients receiving VIRACEPT was diarrhea, which was generally of mild to moderate intensity.

Drug-related clinical adverse experiences of moderate or severe intensity in ≥ 2% of patients treated with VIRACEPT coadministered with d4T and 3TC (Study 542) for up to 48 weeks, or with ZDV plus 3TC (Study 511) for up to 24 weeks are presented in Table 4.

Table 4: Percentage of Patients with Treatment-Emergent* Adverse Events of Moderate or Severe Intensity Reported in ≥ 2% of Adult and Adolescent Patients

Adverse Events Study 511 24 weeks Study 542 48 weeks
Placebo + ZDV/3TC
1250 mg BID VIRACEPT + d4T/3TC
750 mg TID VIRACEPT + d4T/3TC
Digestive System
  Diarrhea 3% 14% 20% 20% 15%
  Nausea 4% 3% 7% 3% 3%
  Flatulence 0 5% 2% 1% 1%
  Rash 1% 1% 3% 2% 1%
* Includes those adverse events at least possibly, probably or definitely related to study drug or of unknown relationship and excludes concurrent HIV conditions

Adverse events occurring in less than 2% of patients receiving VIRACEPT in all phase 2 and 3 clinical trials and considered at least possibly related or of unknown relationship to treatment and of at least moderate severity are listed below.

Body as a Whole: abdominal pain, accidental injury, allergic reaction, asthenia, back pain, fever, headache, malaise, pain, and redistribution/accumulation of body fat [see WARNINGS AND PRECAUTIONS].

Digestive System: anorexia, dyspepsia, epigastric pain, gastrointestinal bleeding, hepatitis, mouth ulceration, pancreatitis, and vomiting.

Hemic/Lymphatic System: anemia, leukopenia, and thrombocytopenia.

Metabolic/Nutritional System: increases in alkaline phosphatase, amylase, creatine phosphokinase, lactic dehydrogenase, SGOT, SGPT, and gamma-glutamyl transpeptidase; hyperlipemia, hyperuricemia, hyperglycemia, hypoglycemia, dehydration, and liver function tests abnormal.

Musculoskeletal System: arthralgia, arthritis, cramps, myalgia, myasthenia, and myopathy.

Nervous System: anxiety, depression, dizziness, emotional lability, hyperkinesia, insomnia, migraine, paresthesia, seizures, sleep disorder, somnolence, and suicide ideation.

Respiratory System: dyspnea, pharyngitis, rhinitis, and sinusitis.

Skin/Appendages: dermatitis, folliculitis, fungal dermatitis, maculopapular rash, pruritus, sweating, and urticaria.

Special Senses: acute iritis and eye disorder.

Urogenital System: kidney calculus, sexual dysfunction, and urine abnormality.

Laboratory Abnormalities

The percentage of patients with marked laboratory abnormalities in Studies 542 and 511 are presented in Table 5. Marked laboratory abnormalities are defined as a Grade 3 or 4 abnormality in a patient with a normal baseline value, or a Grade 4 abnormality in a patient with a Grade 1 abnormality at baseline.

Table 5: Percentage of Patients by Treatment Group with Marked Laboratory Abnormalities* in > 2% of Patients

  Study 511 Study 542
Placebo+ ZDV/3TC
1250 mg BID VIRACEPT+ d4T/3TC
750 mg TID VIRACEPT+ d4T/3TC
  Hemoglobin 6% 3% 2% 0 0
  Neutrophils 4% 3% 5% 2% 1%
  Lymphocytes 1% 6% 1% 1% 0
  ALT (SGPT) 6% 1% 1% 2% 1%
  AST (SGOT)  4% 1% 0 2% 1%
  Creatine Kinase 7% 2% 2% NA NA
* Marked laboratory abnormalities are defined as a shift from Grade 0 at baseline to at least Grade 3 or from Grade 1 to Grade 4

Clinical Trials Experience: Pediatrics (2 to Less than 13 Years of Age)

VIRACEPT has been studied in approximately 400 pediatric patients in clinical trials from birth to 13 years of age. The adverse event profile seen during pediatric clinical trials was similar to that for adults.

The most commonly reported drug-related, treatment-emergent adverse events reported in the pediatric studies included: diarrhea, leukopenia/neutropenia, rash, anorexia, and abdominal pain. Diarrhea, regardless of assigned relationship to study drug, was reported in 39% to 47% of pediatric patients receiving VIRACEPT in 2 of the larger treatment trials. Leukopenia/neutropenia was the laboratory abnormality most commonly reported as a significant event across the pediatric studies.

Postmarketing Experience

The following adverse reactions have been identified during post-approval use of VIRACEPT. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Body as a Whole: hypersensitivity reactions (including bronchospasm, moderate to severe rash, fever, and edema).

Cardiovascular System: QTc prolongation, torsades de pointes.

Digestive System: jaundice.

Metabolic/Nutritional System: bilirubinemia, metabolic acidosis.

Read the entire FDA prescribing information for Viracept (Nelfinavir Mesylate)

Related Resources for Viracept

Read the Viracept User Reviews »

© Viracept Patient Information is supplied by Cerner Multum, Inc. and Viracept Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.


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