Comparative Pharmacology
Head-to-head clinical analysis: ATAZANAVIR SULFATE versus RITONAVIR.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ATAZANAVIR SULFATE versus RITONAVIR.
ATAZANAVIR SULFATE vs RITONAVIR
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Atazanavir is an azapeptide HIV-1 protease inhibitor. It selectively inhibits the virus-specific processing of viral Gag and Gag-Pol polyproteins in HIV-1 infected cells, preventing formation of mature virions.
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.
300 mg orally once daily with ritonavir 100 mg orally once daily, or 400 mg orally once daily without ritonavir (when used alone).
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: ~6.5 to 7 hours; supports 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.
Biliary/fecal: ~79% as unchanged drug; renal: ~13% (including <1% unchanged).
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."