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Fosamprenavir/ritonavir

ViiV Healthcare · FDA-approved active Small molecule

Fosamprenavir is a protease inhibitor that blocks HIV protease, preventing viral replication, while ritonavir acts as a pharmacokinetic booster to increase fosamprenavir levels.

Fosamprenavir is a protease inhibitor that blocks HIV protease, preventing viral replication, while ritonavir acts as a pharmacokinetic booster to increase fosamprenavir levels. Used for HIV-1 infection in treatment-naïve and treatment-experienced patients.

At a glance

Generic nameFosamprenavir/ritonavir
Also known asLexiva/Norvir
SponsorViiV Healthcare
Drug classHIV protease inhibitor
TargetHIV protease
ModalitySmall molecule
Therapeutic areaInfectious Disease
PhaseFDA-approved

Mechanism of action

Fosamprenavir is a prodrug that is converted to amprenavir, which inhibits HIV protease and prevents the cleavage of viral polyproteins necessary for infectious particle maturation. Ritonavir is a potent CYP3A4 inhibitor that dramatically increases fosamprenavir plasma concentrations, allowing for lower and less frequent dosing while maintaining therapeutic efficacy.

Approved indications

Common side effects

Key clinical trials

Primary sources

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SourceUsed for
ClinicalTrials.govTrial enrolment, design, endpoints, results

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