May 23, 2017
Recommended Topic Related To:


"For children who have had HIV-1 infection since birth, the combination drug therapies now used to treat HIV appear to protect against the heart damage seen before combination therapies were available, according to researchers in a National Instit"...



Viracept Side Effects Center

Medical Editor: John P. Cunha, DO, FACOEP

Last reviewed on RxList 4/23/2015

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.

What is Patient Information in Detail?

Easy-to-read and understand detailed drug information and pill images for the patient or caregiver from Cerner Multum.

Viracept in Detail - Patient Information: Side Effects

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

Stop using nelfinavir and call your doctor at once if you have a serious side effect such as:

  • signs of a new infection, such as fever, chills, body aches, flu symptoms, sores in your mouth and throat;
  • high blood sugar (increased thirst, increased urination, hunger, dry mouth, fruity breath odor, drowsiness, dry skin, blurred vision, weight loss);
  • pale skin, feeling light-headed or short of breath, rapid heart rate, trouble concentrating;
  • easy bruising, unusual bleeding (nose, mouth, vagina, or rectum), purple or red pinpoint spots under your skin;
  • rapid heart rate, increased sweating, tremors in your hands, anxiety, feeling irritable, sleep problems (insomnia);
  • diarrhea, unexplained weight loss, menstrual changes, impotence, loss of interest in sex;
  • swelling in your neck or throat (enlarged thyroid);
  • muscle weakness, tired feeling, trouble speaking or swallowing, joint or muscle pain, feeling short of breath;
  • weakness or prickly feeling in your fingers or toes;
  • problems with walking, breathing, speech, swallowing, or eye movement; or
  • severe lower back pain, loss of bladder or bowel control.

Less serious side effects may include:

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

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)

What is Patient Information Overview?

A concise overview of the drug for the patient or caregiver from First DataBank.

Viracept Overview - Patient Information: Side Effects

SIDE EFFECTS: Diarrhea is a common side effect of this medication. If you have diarrhea, ask your doctor or pharmacist about ways to lessen this side effect, such as using anti-diarrhea medicine. Nausea or gas may also occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Some people may experience worsening of a previous medical condition (such as an old infection) as their immune systems improve, or develop new conditions because their immune systems have become overactive. This reaction may occur at any time (soon after starting HIV treatment or many months later). Tell your doctor right away if you have any serious side effects, including: unexplained weight loss, persistent muscle aches/weakness, joint pain, numbness/tingling of the hands/feet/arms/legs, severe tiredness, vision changes, severe/persistent headaches, signs of infection (such as fever, chills, trouble breathing, cough, non-healing skin sores), signs of an overactive thyroid (such as irritability, nervousness, heat intolerance, fast/pounding/irregular heartbeat, bulging eyes, unusual growth in the neck/thyroid known as a goiter), signs of a certain nerve problem known as Guillain-Barre Syndrome (such as difficulty breathing/swallowing/moving your eyes, drooping face, paralysis, slurred speech).

Seek immediate medical attention if any of these rare but serious side effects occur: symptoms of a heart attack (such as chest/jaw/left arm pain, shortness of breath, unusual sweating), easy bruising/bleeding, persistent nausea/vomiting, stomach/abdominal pain, dark urine, yellowing eyes/skin.

This medication may infrequently make your blood sugar level rise, which can cause or worsen diabetes. Tell your doctor immediately if you develop symptoms of high blood sugar such as increased thirst and urination. If you already have diabetes, check your blood sugar levels regularly. Your doctor may need to adjust your diabetes medication, exercise program, or diet.

Changes in body fat may occur while you are taking this medication (such as increased fat in the upper back and stomach areas, decreased fat in the arms and legs). The cause and long-term effects of these changes are unknown. Discuss the risks and benefits of treatment with your doctor, as well as the possible use of exercise to reduce this side effect.

A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Read the entire patient information overview for Viracept (Nelfinavir Mesylate)

What is Prescribing information?

The FDA package insert formatted in easy-to-find categories for health professionals and clinicians.

Viracept FDA Prescribing Information: Side Effects
(Adverse Reactions)


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)

Viracept - User Reviews

Viracept User Reviews

Now you can gain knowledge and insight about a drug treatment with Patient Discussions.

Here is a collection of user reviews for the medication Viracept sorted by most helpful. Patient Discussions FAQs

Report Problems to the Food and Drug Administration


You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

WebMD Daily

Get breaking medical news.