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Viracept Side Effects

Generic Name: nelfinavir

Note: This page contains side effects data for the generic drug nelfinavir. It is possible that some of the dosage forms included below may not apply to the brand name Viracept.

It is possible that some side effects of Viracept may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.

For the Consumer

Applies to nelfinavir: oral powder for suspension, oral tablet

As well as its needed effects, nelfinavir (the active ingredient contained in Viracept) may cause unwanted side effects that require medical attention.

If any of the following side effects occur while taking nelfinavir, check with your doctor immediately:

Less common
  • Confusion
  • dehydration
  • dry or itchy skin
  • fatigue
  • fruity mouth odor
  • increased hunger
  • increased thirst
  • increased urination
  • nausea
  • vomiting
  • weight loss
Incidence not known
  • Abdominal or stomach pain
  • chills
  • clay-colored stools
  • cough
  • dark urine
  • difficulty with breathing
  • dizziness
  • drowsiness
  • fever
  • headache
  • irregular heartbeat
  • loss of appetite
  • muscle tremors
  • noisy breathing
  • rapid, deep breathing
  • recurrent fainting
  • restlessness
  • shortness of breath
  • skin rash
  • stomach cramps
  • tightness in the chest
  • unpleasant breath odor
  • unusual tiredness or weakness
  • vomiting of blood
  • wheezing
  • yellow eyes or skin

Some nelfinavir side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:

More common
  • Diarrhea
Less common
  • Intestinal gas
  • redistribution or accumulation of body fat

For Healthcare Professionals

Applies to nelfinavir: oral powder for reconstitution, oral tablet


Nelfinavir (the active ingredient contained in Viracept) is generally well tolerated with most adverse effects regarded as mild to moderate in severity.[Ref]


Gastrointestinal side effects of moderate or severe intensity have included diarrhea (up to 20%), nausea (up to 7%), and flatulence (up to 5%). Anorexia, dyspepsia, epigastric pain, gastrointestinal bleeding, mouth ulceration, pancreatitis, and vomiting have been reported in less than 2% of patients.[Ref]

Nervous system

Nervous system side effects have included dizziness, hyperkinesia, insomnia, migraine, paresthesia, seizures, sleep disorder, and somnolence in less than 2% of patients.[Ref]


Hematologic side effects have included decreased lymphocytes (up to 6%), neutrophils (up to 5%), and hemoglobin (up to 3%). Anemia, leukopenia, and thrombocytopenia have been reported in less than 2% of patients.

Hematologic side effects associated with protease inhibitors have included spontaneous bleeding in patients with hemophilia A and B. In many of the reported cases, treatment with protease inhibitors was continued or restarted and some patients required additional factor VIII. A causal relationship between protease inhibitor therapy and these episodes has not been established.[Ref]


Hepatic side effects have included elevated AST (SGOT) and elevated ALT (SGPT) in up to 2% of patients. Elevated gamma glutamyl transpeptidase, abnormal liver function tests, and hepatitis have been reported in less than 2% of patients. Jaundice has been reported during postmarketing experience.[Ref]


Other side effects have included abdominal pain, accidental injury, asthenia, back pain, fever, headache, malaise, and pain in less than 2% of patients.[Ref]


Musculoskeletal side effects have included arthralgia, arthritis, cramps, myalgia, myasthenia, and myopathy in less than 2% of patients. Elevated creatine kinase has been reported (up to 2%).[Ref]


Respiratory side effects have included dyspnea, pharyngitis, rhinitis, and sinusitis in less than 2% of patients.[Ref]


Dermatologic side effects of moderate or severe intensity have included rash (up to 3%). Dermatitis, folliculitis, fungal dermatitis, maculopapular rash, pruritus, sweating, and urticaria have been reported in less than 2% of patients.[Ref]


Cardiovascular side effects have included QTc prolongation and torsades de pointes during postmarketing experience.[Ref]


Metabolic side effects have included increased alkaline phosphatase, increased amylase, increased creatine phosphokinase, increased lactic dehydrogenase, hyperlipidemia, hyperuricemia, hyperglycemia, hypoglycemia, and dehydration in less than 2% of patients. Bilirubinemia and metabolic acidosis have been reported during postmarketing experience. Redistribution/accumulation of body fat including central obesity, dorsocervical fat enlargement, peripheral wasting, facial wasting, breast enlargement, and "cushingoid appearance" have been observed in patients receiving protease inhibitors; however, a causal relationship has not been established. New onset diabetes mellitus, exacerbation of preexisting diabetes mellitus, hyperglycemia, and ketoacidosis have been reported during postmarketing experience in patients receiving protease inhibitors.[Ref]


Hypersensitivity side effects have included allergic reaction. Hypersensitivity reactions (including bronchospasm, moderate to severe rash, fever, and edema) have been reported during postmarketing experience.[Ref]


Ocular side effects have included acute iritis and eye disorder in less than 2% of patients.[Ref]


Genitourinary side effects have included kidney calculus, sexual dysfunction, and urine abnormality in less than 2% of patients.[Ref]


Psychiatric side effects have included anxiety, depression, emotional lability, and suicidal ideation in less than 2% of patients.[Ref]


Immunologic side effects have included immune reconstitution syndrome. Autoimmune disorders (e.g., Graves' disease, polymyositis, and Guillain-Barre syndrome) have been reported in the setting of immune reconstitution.


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