Nelfinavir
Pronunciation: (nel-FIN-uh-veer).
- Generic name
- Nelfinavir
- Brand names
- Nelvir, Viracept, Nelfin, Nelvir-250
- Drug class
- Antiretroviral (Protease Inhibitor)
Availability and supply rules vary by country
Trade names by country: United States · Canada
Australia: · Full directory
What Nelfinavir is and how it works
Uses, formulations, monitoring, and supply rules can differ by patient, product, and country. Follow the exact local product information and professional advice.
Mechanism of action: how Nelfinavir works
Nelfinavir inhibits HIV-1 protease by binding to its active site, preventing cleavage of viral polyprotein precursors into mature, functional proteins required for viral replication. This results in the production of immature, non-infectious viral particles, reducing viral load. In vitro data show activity against HIV-2 protease as well, but the FDA-approved clinical indication covers HIV-1 infection only. (1) (2)
What Nelfinavir is used for
HIV-1 infection, in combination with other antiretroviral agents
The FDA-approved indication is specifically HIV-1 infection; nelfinavir is not labeled for HIV-2. It is never used alone (monotherapy) and current treatment guidelines consider it a non-preferred agent given newer alternatives. (2)
Before taking Nelfinavir
Do not take / not appropriate for
- Contraindicated in patients with known hypersensitivity to nelfinavir or its components. (Contraindication) (2)
- Avoid use with drugs highly dependent on CYP3A for clearance (e.g., simvastatin, lovastatin, rifampin, St. (Contraindication) (2)
- John's wort) due to risk of serious or life-threatening reactions. (Contraindication) (2)
Tell your clinician about
(2)How to take Nelfinavir
- General Instructions: Take nelfinavir exactly as prescribed by your healthcare provider, usually with food to improve absorption.. Adult Dosing: The typical adult dose is 1250 mg (five 250 mg tablets) taken twice daily with food, or 750 mg (three 250 mg tablets) taken three times daily with food.. Pediatric Dosing: Dosing for children is based on body weight and should be determined by a pediatric specialist. The oral powder formulation may be used for children who cannot swallow tablets.. Administration: Swallow tablets whole with a meal. Oral powder should be mixed with a suitable liquid or soft food as directed.. When To Stop: Do not stop taking nelfinavir without consulting your healthcare provider, even if you feel well. Stopping suddenly can lead to viral resistance.. Storage: Store at room temperature, away from moisture and heat. Keep out of reach of children.
- This page does not provide a dose calculator. Dosing must follow the prescriber, pharmacist, or product label.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (2)
Missed dose
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and resume your regular schedule. Do not take two doses at once.
Overdose
In case of overdose, seek emergency medical attention or contact a poison control center immediately. Symptoms may include nausea, vomiting, diarrhea, and abdominal pain. Supportive care is recommended. (2)
Side effects
Side effects and their urgency vary; report severe, persistent, or concerning symptoms to a healthcare professional.
Diarrhea
Incidence: Reported in the clinician-authored database; frequency not established
Nausea
Incidence: Reported in the clinician-authored database; frequency not established
Abdominal pain
Incidence: Reported in the clinician-authored database; frequency not established
Vomiting
Incidence: Reported in the clinician-authored database; frequency not established
Rash
Incidence: Reported in the clinician-authored database; frequency not established
Hyperglycemia
Incidence: Reported in the clinician-authored database; frequency not established
Lipodystrophy
Incidence: Reported in the clinician-authored database; frequency not established
Serious warnings
May cause new or worsening diabetes or high blood sugar — serious
Symptoms: May cause new or worsening diabetes or high blood sugar. Can cause liver problems, especially in patients with pre-existing liver disease. May interact with many other medications; inform your healthcare provider of all drugs you take. Can cause changes in body fat distribution (lipodystrophy). Not recommended for use as monotherapy; always use in combination with other antiretrovirals.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2)
Contraindicated in patients with known hypersensitivity to nelfinavir or its components, and with drugs highly dependent on CYP3A for clearance where elevated levels could cause serious or life-threatening reactions — serious
Symptoms: Contraindicated in patients with known hypersensitivity to nelfinavir or its components, and with drugs highly dependent on CYP3A for clearance where elevated levels could cause serious or life-threatening reactions: alfuzosin, amiodarone, quinidine, cisapride, ergot derivatives, lurasidone, pimozide, triazolam, oral midazolam, lovastatin, simvastatin, rifampin, sildenafil (when used for pulmonary arterial hypertension), and St. John's wort. The FDA label states nelfinavir should NOT be used in patients with moderate or severe hepatic impairment (this is a stronger restriction than 'use with caution'). Use with caution in patients with diabetes or hemophilia.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2)
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Drugs highly dependent on CYP3A clearance (contraindicated combination) | Coadministration with alfuzosin, amiodarone, quinidine, cisapride, ergot derivatives, lurasidone, pimozide, triazolam, oral midazolam, lovastatin, simvastatin, rifampin, sildenafil (for pulmonary arterial hypertension), or St. John's wort is contraindicated because elevated levels of these drugs from nelfinavir's CYP3A interaction can cause serious or life-threatening reactions. Always inform your healthcare provider of all medications and supplements you are taking. | (2) |
Pregnancy, breastfeeding, kidney/liver function, age
Pregnancy
The FDA label states nelfinavir should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus; pregnancy-registry data show a slightly elevated birth-defect rate that requires careful clinical consideration. A clinician should weigh HIV treatment needs against this data. (2)
Breastfeeding
Breastfeeding guidance for people with HIV varies by country and clinical context (HIV transmission risk versus infant nutrition/mortality risk), so this decision should be made with a treating clinician rather than from general information. (2)
Children
For children ages 2 to under 13 years, the FDA label dose is 45-55 mg/kg twice daily (maximum 2,500 mg/day) or 25-35 mg/kg three times daily (maximum 2,250 mg/day) with food, using specific weight-based dosing tables. NOTE: this corrects an earlier draft that stated a lower 20-30 mg/kg/dose figure, which did not match the FDA label. Safety and effective dosing have not been established in children under 2 years of age. Current HIV treatment guidelines for children generally do not recommend nelfinavir due to better-studied alternatives. (2)
Renal_impairment
The FDA label states nelfinavir should NOT be used in patients with moderate or severe hepatic impairment; no dose adjustment is specified for mild hepatic impairment or for renal impairment specifically, but caution and clinical monitoring are advised. (2)
Hepatic_impairment
The FDA label states nelfinavir should NOT be used in patients with moderate or severe hepatic impairment; no dose adjustment is specified for mild hepatic impairment or for renal impairment specifically, but caution and clinical monitoring are advised. (2)
Monitoring
(2)Storage
Store at 15-30 degC (59-86 degF) in the original, tightly closed container, away from moisture and heat. Keep out of reach of children.
Professional information
Clinician-facing context only. This section does not replace current product labeling.
General (US FDA label) — adults/adolescents 13+
Indication: HIV-1 infection
Dose summary: 1,250 mg twice daily or 750 mg three times daily with a meal.
Renal context: No specific renal-impairment dose adjustment established in the sources reviewed; not to be used in moderate/severe hepatic impairment. (2)
General (US FDA label) — children 2 to under 13 years
Indication: HIV-1 infection
Dose summary: 45-55 mg/kg twice daily (max 2,500 mg/day) or 25-35 mg/kg three times daily (max 2,250 mg/day) with a meal, per weight-based dosing tables. Corrects an earlier lower figure that did not match the label.
Renal context: No specific renal-impairment dose adjustment established in the sources reviewed. (2)
Frequently asked questions
What is nelfinavir used for?
Nelfinavir is used to treat HIV infection as part of combination antiretroviral therapy. It helps reduce the amount of HIV in the body and improves immune function.
How should I take nelfinavir?
Take nelfinavir with food, exactly as prescribed by your healthcare provider. Swallow the tablets whole, or use the oral powder as directed for children.
What are the most common side effects?
The most common side effects are diarrhea, nausea, abdominal pain, and rash. These are usually mild and temporary.
Can I stop taking nelfinavir if I feel better?
No, do not stop taking nelfinavir without consulting your healthcare provider. Stopping suddenly can lead to drug resistance and treatment failure.
Are there any serious risks with nelfinavir?
Serious risks include liver problems, severe allergic reactions, and high blood sugar. Contact your doctor immediately if you notice symptoms like jaundice, severe rash, or unexplained muscle pain.
Can nelfinavir be used in children?
The FDA label includes weight-based dosing for children ages 2 to under 13 years (45-55 mg/kg twice daily or 25-35 mg/kg three times daily with food). Safety has not been established in children under 2. Current HIV treatment guidelines generally do not recommend nelfinavir for children given better-studied alternatives; a pediatric HIV specialist should make this decision.
What should I do if I miss a dose?
Take the missed dose as soon as you remember, unless it is almost time for your next dose. Do not double up on doses.
What happens if I take too much Nelfinavir?
Taking too much Nelfinavir can lead to an overdose, potentially causing exacerbated side effects like severe gastrointestinal upset. While specific overdose symptoms can vary, it is crucial to seek immediate emergency medical attention if an overdose is suspected. Do not attempt to self-treat and contact poison control or emergency services promptly.
Can I drink alcohol while taking Nelfinavir?
It is generally advisable to limit or avoid alcohol consumption while taking Nelfinavir. Alcohol can increase the risk of certain side effects, particularly those affecting the liver, which is a concern with protease inhibitors. Additionally, alcohol may interfere with the effectiveness of the medication or worsen gastrointestinal symptoms. Always consult your healthcare provider for personalized advice.
Is Nelfinavir safe during pregnancy?
The FDA label states nelfinavir should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus; pregnancy-registry data show a slightly elevated birth-defect rate. Consult your healthcare provider if you are pregnant, planning to become pregnant, or breastfeeding, so they can weigh HIV treatment needs against this data for your situation.
What is the mechanism of action of Nelfinavir?
Nelfinavir inhibits HIV-1 protease by binding to its active site, preventing cleavage of viral polyprotein precursors into mature, functional proteins required for viral replication. This results in the production of immature, non-infectious viral particles, reducing viral load. In vitro data show activity against HIV-2 protease as well, but the FDA-approved clinical indication covers HIV-1 infection only. (1) (2)
What is the generic name of Nelfinavir?
The generic name is Nelfinavir. It is sold under brand names including Nelvir, Viracept, Nelfin, Nelvir-250.
What class of drug is Nelfinavir?
Nelfinavir is classed as: Antiretroviral (Protease Inhibitor).
References
- Nelfinavir clinician-authored medicine recordMedGuideGlobal (internal clinician record) · Global (internal database) · accessed 2026-08-06 · source 1
- VIRACEPT (nelfinavir mesylate) tablets and oral powder – prescribing informationU.S. Food and Drug Administration · United States · accessed 2026-08-06 · source 2
- VIRACEPT (NELFINAVIR MESYLATE) TABLET, FILM COATED [AGOURON] — US prescribing information (DailyMed SPL)U.S. National Library of Medicine (DailyMed) · US · accessed 2026-08-14 · source 3
- Nelfinavir — patient drug information (MedlinePlus)U.S. National Library of Medicine (MedlinePlus) · US · accessed 2026-08-14 · source 4
- VIRACEPT — FDA approval record (Drugs@FDA NDA020779)U.S. Food and Drug Administration · US · accessed 2026-08-14 · source 5
- Nelfinavir — RxNorm normalized drug concept (RXCUI 134527)U.S. National Library of Medicine (RxNorm) · US · accessed 2026-08-14 · source 6
Brand names by country
Single-ingredient Nelfinavir names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
United States
- VIRACEPT625 mg, 250 mg · agouron
Canada
- VIRACEPT