Comparative Pharmacology
Head-to-head clinical analysis: LEXIVA versus RITONAVIR.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LEXIVA versus RITONAVIR.
LEXIVA vs RITONAVIR
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Fosamprenavir is a prodrug of amprenavir, a protease inhibitor (PI) that competitively inhibits HIV-1 protease, preventing cleavage of viral Gag-Pol polyprotein, resulting in immature, non-infectious viral particles.
Ritonavir inhibits HIV protease, preventing cleavage of viral polyprotein precursors into functional proteins, resulting in immature, non-infectious viral particles. It also inhibits CYP3A4, enhancing pharmacokinetics of other protease inhibitors.
1400 mg orally twice daily (with ritonavir 100 mg) or 1400 mg orally once daily (with ritonavir 100 mg and cobicistat 150 mg). For treatment-naïve patients, 1400 mg orally once daily with ritonavir 100 mg or cobicistat 150 mg.
600 mg orally twice daily (oral solution or tablets); as part of boosted protease inhibitor regimen: 100-400 mg orally once or twice daily depending on co-administered PI.
None Documented
None Documented
Clinical Note
moderateRitonavir + Deferasirox
"The serum concentration of Deferasirox can be decreased when it is combined with Ritonavir."
Clinical Note
moderateRitonavir + Estrone sulfate
"The serum concentration of Estrone sulfate can be decreased when it is combined with Ritonavir."
Clinical Note
moderateRitonavir + Triamcinolone
"The risk or severity of adverse effects can be increased when Ritonavir is combined with Triamcinolone."
Clinical Note
moderateRitonavir + Tenofovir disoproxil
Terminal elimination half-life is 2.8 to 5.7 hours; with ritonavir boosting, half-life increases to 7-10 hours, allowing once-daily dosing.
Terminal elimination half-life is approximately 3-5 hours after multiple dosing; however, due to its potent CYP3A4 inhibition, the effective half-life for boosting other protease inhibitors is extended clinically.
Renal (approximately 82% in urine, with 14% as parent drug and 68% as metabolites); fecal (approximately 16%, with 7% as parent drug).
Primarily hepatic metabolism (CYP3A4) with <3.5% excreted unchanged in urine; fecal elimination accounts for ~86% of the dose (mostly metabolites).
Category C
Category A/B
Protease Inhibitor
Protease Inhibitor
"The metabolism of Tenofovir disoproxil can be decreased when combined with Ritonavir."