Comparative Pharmacology
Head-to-head clinical analysis: DARUNAVIR AND RITONAVIR versus LEXIVA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DARUNAVIR AND RITONAVIR versus LEXIVA.
DARUNAVIR AND RITONAVIR vs LEXIVA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Darunavir is a protease inhibitor that binds to the HIV-1 protease active site, preventing cleavage of viral polyproteins into functional proteins, leading to immature, non-infectious virions. Ritonavir is a potent CYP3A4 inhibitor that increases darunavir plasma concentrations by inhibiting its metabolism.
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.
Darunavir 800 mg orally once daily plus ritonavir 100 mg orally once daily in treatment-naïve patients. In treatment-experienced patients with at least one darunavir resistance-associated mutation, darunavir 600 mg plus ritonavir 100 mg orally twice daily.
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.
None Documented
None Documented
Darunavir: ~15 hours (range 10-31 h) when boosted with ritonavir; allows once-daily dosing. Ritonavir: ~3-5 hours (administered as booster).
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.
Darunavir: 79.5% fecal (primarily as unchanged drug), 13.9% renal (mostly metabolites). Ritonavir: 86.4% fecal, 11.3% renal.
Renal (approximately 82% in urine, with 14% as parent drug and 68% as metabolites); fecal (approximately 16%, with 7% as parent drug).
Category A/B
Category C
Protease Inhibitor
Protease Inhibitor