Comparative Pharmacology
Head-to-head clinical analysis: ATAZANAVIR SULFATE versus LOPINAVIR RITONAVIR.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ATAZANAVIR SULFATE versus LOPINAVIR RITONAVIR.
ATAZANAVIR SULFATE vs LOPINAVIR; 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 an HIV-1 protease inhibitor that prevents cleavage of viral Gag-Pol polyprotein precursors, resulting in immature, non-infectious viral particles. Ritonavir is a potent CYP3A4 inhibitor used at low doses to boost lopinavir plasma levels.
300 mg orally once daily with ritonavir 100 mg orally once daily, or 400 mg orally once daily without ritonavir (when used alone).
Lopinavir 400 mg / Ritonavir 100 mg (two tablets or 5 mL oral solution) orally twice daily with food. Alternatively, once-daily dosing (800/200 mg) may be used in treatment-naïve patients with <3 lopinavir resistance mutations.
None Documented
None Documented
Terminal elimination half-life: ~6.5 to 7 hours; supports once-daily dosing.
Lopinavir: 5-6 hours; Ritonavir: 3-5 hours. When coadministered, ritonavir inhibits lopinavir metabolism, resulting in a prolonged lopinavir half-life (~5-6 hours) allowing twice-daily dosing.
Biliary/fecal: ~79% as unchanged drug; renal: ~13% (including <1% unchanged).
Primarily hepatic metabolism via CYP3A4; fecal excretion of metabolites (approximately 82-90%); renal excretion of unchanged drug is negligible (<3%).
Category C
Category A/B
Protease Inhibitor
Protease Inhibitor