Comparative Pharmacology
Head-to-head clinical analysis: ATAZANAVIR SULFATE versus LOPINAVIR AND RITONAVIR.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ATAZANAVIR SULFATE versus LOPINAVIR AND RITONAVIR.
ATAZANAVIR SULFATE vs LOPINAVIR AND 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.
Lopinavir is a HIV-1 protease inhibitor that prevents cleavage of viral Gag-Pol polyproteins, resulting in immature, non-infectious viral particles. Ritonavir is a potent CYP3A4 inhibitor that increases lopinavir plasma concentrations; at subtherapeutic doses, it also inhibits HIV-1 protease.
300 mg orally once daily with ritonavir 100 mg orally once daily, or 400 mg orally once daily without ritonavir (when used alone).
Lopinavir/ritonavir 400/100 mg (two tablets of 200/50 mg or 5 mL oral solution 80/20 mg per mL) orally twice daily with food.
None Documented
None Documented
Terminal elimination half-life: ~6.5 to 7 hours; supports once-daily dosing.
Lopinavir terminal elimination half-life is approximately 5–6 hours (range 4–8 h) when co-administered with ritonavir. Ritonavir half-life is about 3–5 hours. The prolonged half-life of lopinavir in the presence of ritonavir supports twice-daily dosing; steady state is reached within 2–3 days.
Biliary/fecal: ~79% as unchanged drug; renal: ~13% (including <1% unchanged).
Lopinavir is primarily eliminated via hepatic metabolism (CYP3A4), with <3% excreted unchanged in urine and ~20% excreted unchanged in feces. Ritonavir is also predominantly hepatically metabolized, with <3.5% excreted unchanged in urine and ~86% eliminated in feces (mostly as metabolites).
Category C
Category A/B
Protease Inhibitor
Protease Inhibitor