Nelfinavir

Moderate or severe (Child-Pugh class B or C, score ≥7): Not recommended.

Nelfinavir Should be taken with food. Patients unable to swallow may dissolve the tab in a small amount of water. Mix the cloudy liquid well, then take the mixture immediately. Rinse the glass with water, then drink to get the full dose. Alternatively, the tab may be crushed, mixed with small amount of non-acidic food or juice, then taken immediately.

Hypersensitivity. Concomitant use with drugs highly dependent on CYP3A for clearance (e.g. alfuzosin, amiodarone, quinidine, cisapride, ergot derivatives [e.g. dihydroergotamine, ergotamine, methylergonovine], lovastatin, simvastatin, lurasidone, pimozide, rifampicin, sildenafil [used for pulmonary arterial hypertension], oral midazolam, triazolam, St. John's wort), in which significantly increased or decreased nelfinavir plasma concentrations may result in serious events.

Patient with diabetes, haemophilia A or B; hepatitis B or C co-infection, cirrhosis. Renal and hepatic impairment. Children. Pregnancy; breastfeeding is not recommended to avoid transmission of HIV.

Significant: Diarrhoea, nausea; fat redistribution or lipodystrophy (e.g. central obesity, dorsocervical fat enlargement [buffalo hump], peripheral wasting, facial wasting, breast enlargement, Cushingoid appearance); immune reconstitution syndrome, which may lead to inflammatory response to opportunistic infection during initial treatment or activation of autoimmune disorder later in therapy; increased bleeding, including spontaneous skin haematomas or haemarthrosis (particularly for patients with haemophilia A or B); hyperglycaemia, new-onset or exacerbation of diabetes, diabetic ketoacidosis.
Blood and lymphatic system disorders: Anaemia, lymphocytopenia, thrombocytopenia.
Cardiac disorders: Bradycardia, torsades de pointes.
Eye disorders: Acute iritis, eye disease.
Gastrointestinal disorders: Dyspepsia, abdominal or epigastric pain, flatulence, gastrointestinal haemorrhage, mouth ulceration, vomiting, pancreatitis.
General disorders and administration site conditions: Asthenia, malaise, fever.
Hepatobiliary disorders: Jaundice.
Immune system disorders: Hypersensitivity reactions.
Investigations: Increased lactate dehydrogenase, GGT, serum ALT, serum alkaline phosphatase, and serum AST; increased creatine phosphokinase and amylase; prolonged QT interval.
Metabolism and nutrition disorders: Dehydration, anorexia, hyperlipidaemia, hyperuricaemia, hypoglycaemia, metabolic acidosis, hyperbilirubinaemia, hypertriglyceridaemia.
Musculoskeletal and connective tissue disorders: Arthralgia, arthritis, back pain, hyperkinetic muscle activity, muscle cramps, myalgia, myopathy, myositis, osteonecrosis.
Nervous system disorders: Headache, dizziness, drowsiness, paraesthesia, seizure.
Psychiatric disorders: Anxiety, depression, insomnia, emotional lability.
Renal and urinary disorders: Urine abnormality, nephrolithiasis.
Reproductive system and breast disorders: Sexual disorder.
Respiratory, thoracic and mediastinal disorders: Dyspnoea, pharyngitis, rhinitis, sinusitis.
Skin and subcutaneous tissue disorders: Dermatitis, diaphoresis, folliculitis, fungal dermatitis, pruritus, rash, urticaria.
Potentially Fatal: Hepatitis or worsening of pre-existing hepatic disease.

Monitor liver function, viral load, CD4 count, triglycerides, cholesterol, blood glucose levels, and CBC with differential. Assess for signs of gastrointestinal disturbances (e.g. diarrhoea, nausea), hyperglycaemia, and development of new-onset or worsening of existing diabetes mellitus.

Increased plasma concentration or risk of adverse effects of indinavir, saquinavir, bosentan, corticosteroids (e.g. fluticasone), β₂-agonists (e.g. salmeterol), macrolides (e.g. azithromycin), immunosuppressants (e.g. ciclosporin, tacrolimus, sirolimus), antidepressants (e.g. trazodone), and colchicine. May reduce the plasma levels of delavirdine and methadone. May alter the concentration of warfarin. Decreased plasma concentration which may result in loss of therapeutic effect with certain anticonvulsants (e.g. carbamazepine, phenobarbital, phenytoin), omeprazole and non-nucleoside reverse transcriptase inhibitors (e.g. nevirapine). Reduced effectiveness of oral contraceptives (e.g. ethinylestradiol, norethindrone).
Potentially Fatal: Increased plasma concentrations and risk of serious toxicity of α₁-blockers (e.g. alfuzosin), antiarrhythmics (e.g. amiodarone, quinidine), ergot derivatives (e.g. ergotamine, dihydroergotamine, methylergonovine), statins (e.g. simvastatin, lovastatin), antipsychotics (e.g. lurasidone, pimozide), phosphodiesterase 5 (PDE₅) inhibitors used in pulmonary arterial hypertension (e.g. sildenafil), sedative/hypnotics (e.g. oral midazolam, triazolam), and cisapride. Decreased nelfinavir serum level which may result in loss of therapeutic effect or development of resistance with rifampicin.

Increased AUC by two- to threefold when taken with food. Avoid mixing with acidic foods (e.g. applesauce) or juices (e.g. orange juice, apple juice) as this may cause a bitter taste. Decreased serum concentration which may result in loss of therapeutic effect with St. John's wort.

Description:
Overview: Nelfinavir is a selective HIV protease inhibitor.
Mechanism of Action: Nelfinavir binds to the HIV-1 protease activity site, which prevents the cleavage of viral Gag-Pol polyprotein precursors into functional proteins required for infectious HIV, resulting in immature and non-infectious viral particle formation.
Pharmacodynamics: The complete mechanism(s) of resistance or decreased susceptibility to nelfinavir have not been fully elucidated; however, mutation of HIV protease appears to be the main mechanism of resistance. Based on clinical trials in patients receiving nelfinavir, ≥1 viral protease mutations were identified in HIV-1 patients with evaluable isolates. HIV variants with mutations at protease amino acid positions 30, 35, 36, 46, 71, 77 and 88 have been isolated. Overall incidence of D30N substitution in the viral protease of isolates from patients taking monotherapy or combination therapy with zidovudine and lamivudine/stavudine was 54.8%, while L90M substitutions associated with protease inhibitor resistance was 9.6%.

Evidence from in vitro and in vivo studies showed that the degree of cross-resistance can vary among various HIV protease inhibitors. Isolates carrying D30N substitution with high-level nelfinavir resistance generally remain susceptible to amprenavir, indinavir, lopinavir, and saquinavir in vitro, whereas those with L90M substitution may show moderate to high-level resistance to nelfinavir and varying susceptibility levels to amprenavir, indinavir, lopinavir and saquinavir in vitro. Cross-resistance with reverse transcriptase inhibitors is unlikely since they act on different enzyme targets.
Pharmacokinetics:
Absorption: Absorbed from the gastrointestinal tract. Increased area under the plasma concentration time curve (AUC) by two- to threefold with food. Bioavailability: 20-80%. Time to peak plasma concentration: 2-4 hours.
Distribution: Crosses the placenta and enters breast milk. Volume of distribution: 2-7 L/kg. Plasma protein binding: >98%.
Metabolism: Metabolised in the liver via oxidation by CYP3A4 and CYP2C19 to form a major metabolite with activity equal to nelfinavir.
Excretion: Mainly via faeces (98-99%; 78% as metabolites, 22% as unchanged drug); urine (1-2% as unchanged drug). Elimination half-life: 3.5-5 hours.

Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 64143, Nelfinavir. https://pubchem.ncbi.nlm.nih.gov/compound/Nelfinavir. Accessed Jan. 28, 2026.

Store between 15-30°C.

Antivirals

J05AE04 - nelfinavir ; Belongs to the class of protease inhibitors. Used in the systemic treatment of viral infections.

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Nelfinavir Mesylate. UpToDate Lexidrug, AHFS DI (Adult and Pediatric) Online. American Society of Health-System Pharmacists, Inc. Waltham, MA. UpToDate, Inc. https://online.lexi.com. Accessed 19/11/2025.

Nelfinavir. UpToDate Lexidrug, Lexi-Drugs Multinational Online. Waltham, MA. UpToDate, Inc. https://online.lexi.com. Accessed 19/11/2025.

Viracept Tablet, Film Coated (Agouron Pharmaceuticals, LLC). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 19/11/2025.