Comparative Pharmacology
Head-to-head clinical analysis: EVOTAZ versus FOSAMPRENAVIR CALCIUM.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EVOTAZ versus FOSAMPRENAVIR CALCIUM.
EVOTAZ vs FOSAMPRENAVIR CALCIUM
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
EVOTAZ is a fixed-dose combination of atazanavir, an HIV-1 protease inhibitor, and cobicistat, a CYP3A inhibitor. Atazanavir inhibits HIV-1 protease, preventing cleavage of viral polyproteins and resulting in immature, non-infectious virions. Cobicistat increases systemic exposure of atazanavir by inhibiting CYP3A-mediated metabolism.
Fosamprenavir is a prodrug of amprenavir, an HIV-1 protease inhibitor. It binds to the active site of HIV-1 protease, preventing cleavage of viral Gag-Pol polyproteins, resulting in immature, non-infectious viral particles.
1 tablet (300 mg atazanavir and 150 mg cobicistat) orally once daily with food.
1400 mg orally twice daily or 1400 mg once daily plus ritonavir 100 mg or 200 mg once daily plus ritonavir 100 mg. Alternatively, fosamprenavir 700 mg plus ritonavir 100 mg twice daily.
None Documented
None Documented
Cobicistat: terminal half-life approximately 3–4 hours; atazanavir: terminal half-life approximately 7 hours (range 5–12 hours) at steady state when boosted with cobicistat. The short half-life of cobicistat necessitates once-daily dosing with atazanavir to maintain therapeutic concentrations.
Terminal elimination half-life is approximately 7.7 hours; supports twice-daily dosing.
Cobicistat: primarily hepatic metabolism (CYP3A4) and biliary/fecal excretion; <7% excreted unchanged renally. Atazanavir: primarily biliary/fecal excretion as unchanged drug and metabolites (79–88%); renal excretion accounts for <7%.
Primarily hepatic metabolism via CYP3A4, with 14% renal excretion of unchanged drug; 68% fecal, 1% urinary as unchanged drug.
Category C
Category A/B
Protease Inhibitor
Protease Inhibitor