Nelfinavir

Indications

Nelfinavir is indicated for the treatment of HIV infection when antiretroviral therapy is warranted

Pharmacology

Nelfinavir is a selective, competitive, reversible HIV protease inhibitor. It inhibits HIV-1 protease preventing the cleavage of the gag-pol polyprotein resulting in the production of noninfectious virus.

Dosage & Administration

Adults: The recommended dose is 1250 mg (five 250 mg tablets) twice daily or 750 mg (three 250 mg tablets) three times daily. Nelfinavir should be taken with a meal. Antiviral activity is enhanced when Nelfinavir is administered in combination with nucleoside analogues. Therefore, it is recommended that Nelfinavir should be used in combination with nucleoside analogues.

Paediatric patients (2-13 years): The recommended oral dose of Nelfinavir for paediatric patients 2 to 13 years of age is 20-30 mg/kg per dose, three times daily with a meal.

Interaction

Reduced levels/effects with antacids, phenobarbital, carbamazepine, aminoglutethimide, phenytoin, rifampicin, nafcillin, nevirapine, omeprazole, nevirapine. Increased serum levels/effects with azole antifungal agents, cimetidine, efavirenz. Increased serum levels/effects of azithromycin, calcium channel blockers, clarithromycin, corticosteroids (e.g. fluticasone), mirtazapine, nateglinide, nefazodone, ciclosporin, sirolimus, tacrolimus, venlafaxine, eplerinone, fentanyl, atorvastatin, phosphodiesterase-5 (PDE-5) inhibitors, rifabutin, trazodone, TCAs. Reduced serum levels/effects of hormonal contraceptives, methadone, theophylline derivatives.

Contraindications

Nelfinavir is contraindicated in patients with clinically significant hypersensitivity to any of its components. Co-administration of Avifix is contraindicated with drugs that are highly dependent on CYP3A for clearance and for which elevated plasma concentrations are associated with serious and/or life-threatening adverse events

Side Effects

The safety of Nelfinavir was studied in over 1500 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 Nelfinavir was diarrhoea, which was generally of mild to moderate intensity. Adverse events occurring in less than 2% of patients receiving Nelfinavir in all phase II/III clinical trials and considered at least possibly related or of unknown relationship to treatment and of at least moderate severity are listed below.

General: Abdominal pain, accidental injury, allergic reaction, asthenia, back pain, fever, headache, malaise, pain and redistribution/accumulation of body fat.

Digestive system: Anorexia, dyspepsia, epigastric pain, gastrointestinal bleeding, hepatitis, mouth ulceration, pancreatitis and vomiting.

Haemic/Lymphatic system: Anaemia, leukopenia and thrombocytopenia.

Metabolic/Nutritional: Increase in alkaline phosphate, amylase, creatinine phosphokinase, lactic dehydrogenase, SGOT, SGPT and g glutamyl transpeptidase, hyperlipaemia, hyperuricaemia, hyperglycaemia, hypoglycaemia, 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, paraesthesia, seizures, sleep disorder, somnolence and suicide ideation.

Respiratory system: Dyspnoea, pharyngitis, rhinitis and sinusitis.

Skin/Appendages: Dermatitis, folliculitis, fungal dermatitis, maculopapular rash, pruitus, sweating, and urticaria.

Ophthalmic: Acute iritis and eye disorder.

Urogenital system: Kidney calculas, sexual dysfunction.

Pregnancy & Lactation

Pregnancy Category B. There are no adequate and well controlled studies in pregnant women.

Lactation: The US Public Health Service Centers for Disease Control and Prevention advises HIV-infected women not to breast-feed to avoid postnatal transmission of HIV to a child.

Precautions & Warnings

Nelfinavir should not be administered concurrently with Terfenadine, Astemizole, Cisapride, Triazolam, Midazolam, Ergot derivatives, Amiodarone or Quinidine because Nelfinavir may affect the hepatic metabolism of these drugs and create potential for serious and/or life-threatening adverse events. New onset diabetes mellitus, exacerbation of pre-existing diabetes mellitus and hyperglycaemia have been reported during post-marketing surveillance in HIV-infected patients receiving protease inhibitor therapy. Some patients required either initiation or dose adjustments of insulin or oral hypoglycaemic agents for treatment of these events. In some cases diabetic ketoacidosis has occurred. In those patients who discontinued protease inhibitor therapy, hyperglycaemia persisted in some cases.

General: Nelfinavir is principally metabolised by the liver. Therefore, caution should be exercised when administering this drug to patients with hepatic impairment.

Haemophilia: There have been reports of increased bleeding, including spontaneous skin haematomas and haemarthrosis, in patients with haemophilia type A and B treated with protease inhibitors. In some patients, additional factor VIII was given. In more than half of the reported cases, treatment with protease inhibitors was continued or reintroduced. A causal relationship has not been established.

Use in Special Populations

Paediatric use: The safety, effectiveness and pharmacokinetics of Nelfinavir have not been evaluated in paediatric patients below the age of 2 years.

Therapeutic Class

Drugs for HIV / Anti-retroviral drugs

Storage Conditions

Store at 15-30° C

Available Brand Names