Skip to Content

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


Most side effects were of mild severity. The most common side effect was diarrhea, which was usually of mild to moderate severity.[Ref]


Very common (10% or more): Diarrhea (up to 20%)
Common (1% to 10%): Nausea, flatulence
Frequency not reported: Abdominal pain, dyspepsia, epigastric pain, gastrointestinal bleeding, increased amylase, mouth ulceration, pancreatitis, vomiting[Ref]


Common (1% to 10%): Decreased lymphocytes, decreased neutrophils, decreased hemoglobin
Frequency not reported: Anemia, leukopenia, thrombocytopenia

HIV protease inhibitor therapy:
-Frequency not reported: Increased bleeding (including spontaneous skin hematomas, hemarthrosis) in hemophiliacs[Ref]

Increased bleeding (including spontaneous skin hematomas and hemarthrosis) in patients with hemophilia type A and B has been associated with protease inhibitors. 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]


Common (1% to 10%): Elevated AST, elevated ALT
Frequency not reported: Elevated GGT, abnormal liver function tests, hepatitis
Postmarketing reports: Jaundice, bilirubinemia[Ref]


Common (1% to 10%): Elevated creatine kinase
Frequency not reported: Arthralgia, arthritis, back pain, cramps, increased creatine phosphokinase, myalgia, myasthenia, myopathy[Ref]


Common (1% to 10%): Rash
Frequency not reported: Dermatitis, folliculitis, fungal dermatitis, maculopapular rash, pruritus, sweating, urticaria[Ref]

Nervous system

Frequency not reported: Dizziness, headache, hyperkinesia, migraine, paresthesia, seizures, somnolence[Ref]


Frequency not reported: Accidental injury, asthenia, fever, malaise, pain[Ref]


Frequency not reported: Dyspnea, pharyngitis, rhinitis, sinusitis[Ref]


Postmarketing reports: QTc prolongation, torsades de pointes[Ref]


Frequency not reported: Anorexia, increased alkaline phosphatase, increased LDH, hyperlipidemia, hyperuricemia, hyperglycemia, hypoglycemia, dehydration, redistribution/accumulation of body fat
Postmarketing reports: Metabolic acidosis

Combination antiretroviral therapy:
-Frequency not reported: Redistribution/accumulation of body fat (including central obesity, dorsocervical fat enlargement, peripheral wasting, facial wasting, breast enlargement, "cushingoid appearance")

HIV protease inhibitor therapy:
-Postmarketing reports: New onset diabetes mellitus, exacerbation of preexisting diabetes mellitus, hyperglycemia, ketoacidosis[Ref]


Frequency not reported: Anxiety, depression, emotional lability, insomnia, sleep disorder, suicidal ideation[Ref]


Frequency not reported: Allergic reaction
Postmarketing reports: Hypersensitivity reactions (including bronchospasm, moderate to severe rash, fever, edema)[Ref]


Frequency not reported: Kidney calculus[Ref]


Frequency not reported: Sexual dysfunction, urine abnormality[Ref]


Frequency not reported: Immune reconstitution/reactivation syndrome, autoimmune disorders in the setting of immune reconstitution (e.g., Graves' disease, polymyositis, Guillain-Barre syndrome)


Frequency not reported: Acute iritis, eye disorder[Ref]


1. "Product Information. Viracept (nelfinavir)." Agouron Pharma Inc, La Jolla, CA.

2. AIDSinfo. NIH. National Institutes of Health "Guidelines for the use of antiretroviral agents in pediatric HIV infection. Available from: URL:" ([2015 Mar 5]):

3. HHS Panel on Antiretroviral Guidelines for Adults and Adolescents. Office of AIDS Research Advisory Council (OARAC). NIH. National Institutes of Health "Guidelines for the use of antiretroviral agents in HIV-1-infected adults and adolescents. Available from: URL:" ([2015 Apr 8]):

4. Warnke D, Barreto J, Temesgen Z "Antiretroviral drugs." J Clin Pharmacol 47 (2007): 1570-9

5. Flanigan TP, Ramratnam B, Graeber C, Hellinger J, Smith D, Wheeler D, Hawley P, Heathchiozzi M, Ward DJ, Brummitt C, Turner J "Prospective trial of paromomycin for cryptosporidiosis in AIDS." Am J Med 100 (1996): 370-2

6. Gathe J, Burkhardt B, Hawley P, Conant M, Peterkin J, Chapman S "A randomized phase II study of VIRACEPT, a novel HIV proteas inhibitor, used in combination with stavudine (d4T) vs. stavudin (d4T) alone." Int Conf AIDS 11 (1996): 25(

7. Damle B, Hewlett D Jr, Hsyu PH, Becker M, Petersen A "Pharmacokinetics of nelfinavir in subjects with hepatic impairment." J Clin Pharmacol 46 (2006): 1241-9

8. "Drugs for HIV infection." Med Lett Drugs Ther 43 (2001): 103-8

9. Timmermans S, Tempelman C, Godfried MH, et al. "Nelfinavir and nevirapine side effects during pregnancy." AIDS 19 (2005): 795-799

10. Regazzi M, Maserati R, Villani P, et al. "Clinical Pharmacokinetics of Nelfinavir and Its Metabolite M8 in Human Immunodeficiency Virus (HIV)-Positive and HIV-Hepatitis C Virus-Coinfected Subjects." Antimicrob Agents Chemother 49 (2005): 643-9

11. Gathe JC Jr, Ive P, Wood R, et al. "SOLO: 48-week efficacy and safety comparison of once-daily fosamprenavir /ritonavir versus twice-daily nelfinavir in naive HIV-1-infected patients." AIDS 18 (2004): 1529-1537

12. Guest JL, Ruffin C, Tschampa JM, DeSilva KE, Rimland D "Differences in rates of diarrhea in patients with human immunodeficiency virus receiving lopinavir-ritonavir or nelfinavir." Pharmacotherapy 24 (2004): 727-35

13. Ghosn J, Lamotte C, Ait-Mohand H, et al. "Efficacy of a twice-daily antiretroviral regimen containing 100 mg ritonavir/400 mg indinavir in HIV-infected patients." AIDS 17 (2003): 209-14

14. Aarnoutse RE, Droste JA, Van Oosterhout JJ, et al. "Pharmacokinetics, food intake requirements and tolerability of once-daily combinations of nelfinavir and low-dose ritonavir in healthy volunteers." Br J Clin Pharmacol 55 (2003): 115-125

15. Hsyu PH, Schultz-Smith MD, Lillibridge JH, Lewis RH, Kerr BM "Pharmacokinetic Interactions between Nelfinavir and 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase Inhibitors Atorvastatin and Simvastatin." Antimicrob Agents Chemother 45 (2001): 3445-50

16. "Drugs for HIV infection." Treat Guidel Med Lett 7 (2009): 11-22

17. Carr A "HIV protease inhibitor-related lipodystrophy syndrome." Clin Infect Dis 30 (2000): s135-42

18. Perry CM, Frampton JE, McCormack PL, Siddiqui MA, Cvetkovic RS "Nelfinavir: A Review of its Use in the Management of HIV Infection." Drugs 65 (2005): 2209-44

19. Heeswijk RP, Khaliq Y, Gallicano KD, et al. "The pharmacokinetics of nelfinavir and M8 during pregnancy and post partum." Clin Pharmacol Ther 76 (2004): 588-97

20. Moyle GJ, Youle M, Higgs C, Monaghan J, Peterkin J, Chapman S, Nelson M "Extended follow-up of safety and activity of agouron's HIV proteinas inhibitor ag1343 (Viracept) in virological responders from the UK phase I/II dose finding study." Int Conf AIDS 11 (1996): 18(

21. Marzolini C, Buclin T, Decosterd LA, Biollaz J, Telenti A "Nelfinavir plasma levels under twice-daily and three-times-daily regimens: High interpatient and low intrapatient variability." Ther Drug Monit 23 (2001): 394-8

22. Puro V, Soldani F, De Carli G, Lazarevic Z, Mattioli F, Ippolito G "Drug-induced aminotransferase alterations during antiretroviral HIV post-exposure prophylaxis." AIDS 17 (2003): 1988-90

23. Abraham PE, Sorensen SJ, Baker WH, Cushing HE "Nelfinavir desensitization." Ann Pharmacother 35 (2001): 553-6

24. Manfredi R, Calza L, Chiodo F "Gynecomastia associated with highly antiretroviral therapy." Ann Pharmacother 35 (2001): 438-9

25. Martinez E, Mocroft A, GarciaViejo MA, PerezCuevas JB, Blanco JL, Mallolas J, Bianchi L, Conget I, Blanch J, Phillips A, Gatell "Risk of lipodystrophy in HIV-1-infected patients treated with protease inhibitors: a prospective cohort study." Lancet 357 (2001): 592-8

26. Dube MP, Parker RA, Tebas P, et al. "Glucose metabolism, lipid, and body fat changes in antiretroviral-naive subjects randomized to nelfinavir or efavirenz plus dual nucleosides." AIDS 19 (2005): 1807-1818

27. Bergersen BM "Cardiovascular Risk in Patients with HIV Infection : Impact of Antiretroviral Therapy." Drugs 66 (2006): 1971-87

28. Fantoni M, Del Borgo C, Autore C "Evaluation and management of metabolic and coagulative disorders in HIV-infected patients receiving highly active antiretroviral therapy." AIDS 17 Suppl 1 (2003): S162-9

29. Fisac C, Virgili N, Ferrer E, et al. "A comparison of the effects of nevirapine and nelfinavir on metabolism and body habitus in antiretroviral-naive human immunodeficiency virus-infected patients: a randomized controlled study." J Clin Endocrinol Metab 88 (2003): 5186-92

30. Engeler DS, John H, Rentsch KM, Ruef C, Oertle D, Suter S "Nelfinavir urinary stones." J Urol 167 (2002): 1384-5

31. Roling J, Schmid H, Fischereder M, Draenert R, Goebel FD "HIV-Associated Renal Diseases and Highly Active Antiretroviral Therapy-Induced Nephropathy." Clin Infect Dis 42 (2006): 1488-95

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.