Lexiva: Full Drug Profile

Lexiva - General Information

Lexiva is a prodrug of amprenavir, an inhibitor of human immunodeficiency virus (HIV) protease.

Pharmacology of Lexiva

Lexiva is a pro-drug of the protease inhibitor and antiretroviral drug amprenavir. The human body metabolizes fosamprenavir in order to form amprenavir, which is the active ingredient. That metabolization increases the duration that amprenavir is available, making fosamprenavir a slow-release version of amprenavir and thus reducing the number of pills required versus standard amprenavir.

Lexiva for patients

Lexiva Interactions

Lexiva Contraindications

LEXIVA is contraindicated:

• in patients with previously demonstrated clinically significant hypersensitivity (e.g., Stevens-Johnson syndrome) to any of the components of this product or to amprenavir.
• when coadministered with drugs that are highly dependent on CYP3A4 for clearance and for which elevated plasma concentrations are associated with serious and/or life-threatening events (Table 1).

Table 1. Drugs Contraindicated With LEXIVA

• when coadministered with ritonavir in patients receiving the antiarrhythmic agents flecainide and propafenone. If LEXIVA is coadministered with ritonavir, reference should be made to the full prescribing information for ritonavir for additional contraindications.

Additional information about Lexiva

Lexiva Indication: Indicated in combination with other antiretroviral agents for the treatment of human immunodeficiency virus (HIV-1) infection. Mechanism Of Action: Lexiva is a prodrug that is rapidly hydrolyzed to amprenavir by cellular phosphatases in the gut epithelium as it is absorbed. Amprenavir is an inhibitor of HIV-1 protease. Amprenavir binds to the active site of HIV-1 protease and thereby prevents the processing of viral Gag and Gag-Pol polyprotein precursors, resulting in the formation of immature non-infectious viral particles. Drug Interactions: Alprazolam Amprenavir increases the effect and toxicity of benzodiazepineClorazepate Amprenavir increases the effect and toxicity of benzodiazepineDiazepam Amprenavir increases the effect and toxicity of benzodiazepineFlurazepam Amprenavir increases the effect and toxicity of benzodiazepineMidazolam Amprenavir increases the effect and toxicity of benzodiazepineTriazolam Amprenavir increases the effect and toxicity of benzodiazepineWarfarin The protease inhibitor increases the anticoagulant effectAcenocoumarol The protease inhibitor increases the anticoagulant effectDicumarol The protease inhibitor increases the anticoagulant effectAnisindione The protease inhibitor increases the anticoagulant effectAluminium The antiacid decreases the absorption of amprenavirBismuth The antiacid decreases the absorption of amprenavirCalcium The antiacid decreases the absorption of amprenavirMagnesium oxide The antiacid decreases the absorption of amprenavirMagnesium The antiacid decreases the absorption of amprenavirAmiodarone The protease inhibitor increases the effect and toxicity of amiodaroneAstemizole Increased risk of cardiotoxicity and arrhythmiasTerfenadine Increased risk of cardiotoxicity and arrhythmiasAtorvastatin Amprenavir can possibly increase the statin toxicityLovastatin Amprenavir can possibly increase the statin toxicitySimvastatin Amprenavir can possibly increase the statin toxicityBepridil Amprenavir increases the effect and toxicity of bepridilCisapride Amprenavir increases the effect and toxicity of cisaprideCyclosporine The protease inhibitor increases the effect of cyclosporineDelavirdine Decreased levels of delavirdine with increased levels of amprenavirDihydroergotamine Amprenavir increases the effect and toxicity of ergot derivativeErgotamine Amprenavir increases the effect and toxicity of ergot derivativeFentanyl The protease inhibitor increases the effect and toxicity of fentanylFusidic Acid The protease inhibitor increases the effect and toxicity of fusidic acidMethadone The protease inhibitor decreases the effect of methadonePimozide Amprenavir increases the effect and toxicity of pimozideRanolazine Increased levels of ranolazine - risk of toxicityRifabutin Amprenavir increases the effect and toxicity of rifabutinRifampin In presence of rifampin anticipate decrease of amprenavir efficiencySildenafil The protease inhibitor increases the effect and toxicity of sildenafilSt. John's Wort St. John's Wort decreases the effect of indinavirTacrolimus The protease inhibitor increases the effect and toxicity of tacrolimusVardenafil The protease inhibitor increases the effect and toxicity of Food Interactions: Avoid alcohol, especially with the oral solution since it contains propylene glycol which competes with alcohol for alcohol dehydrogenase metabolism.Take with or without food, however avoid lipid-rich meals.Vitamin E increases fosamprenavir bioavailability. Generic Name: Fosamprenavir Synonyms: Not Available Drug Category: Anti-HIV Agents; HIV Protease Inhibitors; Prodrugs Drug Type: Small Molecule; Approved Other Brand Names containing Fosamprenavir: Lexiva; Telzir; Absorption: The absolute oral bioavailability of amprenavir after administration of fosamprenavir in humans has not been established. After administration of a single 1,400 mg dose in the fasted state, fosamprenavir oral suspension (50 mg/mL) and fosamprenavir tablets (700 mg) provided similar amprenavir exposures (AUC), however, the Cmax of amprenavir after administration of the suspension formulation was 14.5 % higher compared with the tablet. Toxicity (Overdose): Not Available Protein Binding: Very high (approximately 90%); primarily bound to alpha 1 -acid glycoprotein. Higher amounts of unbound amprenavir present as amprenavir serum concentrations increase. Biotransformation: In the gut epithelium during absorption, fosamprenavir is rapidly and almost completely hydrolyzed to amprenavir and inorganic phosphate prior to reaching the systemic circulation. Amprenavir is metabolized in the liver by the cytochrome P450 3A4 (CYP3A4) enzyme system. Half Life: The plasma elimination half-life of amprenavir (the active metabolite) is approximately 7.7 hours. Dosage Forms of Lexiva: Tablet OralSuspension Oral Chemical IUPAC Name: [(3S)-oxolan-3-yl] N-[(2S,3R)-4-[(4-aminophenyl)sulfonyl-(2-methylpropyl)amino]-1-phenyl-3-phosphonooxybutan-2-yl]carbamate Chemical Formula: C25H36N3O9PS Fosamprenavir on Wikipedia: https://en.wikipedia.org/wiki/Fosamprenavir Organisms Affected: Human Immunodeficiency Virus