narlaprevir + ritonavir

Narlaprevir + ritonavir is an **oral, small molecule combination therapy** developed for the treatment of **hepatitis C virus (HCV) infection, genotype 1**. Narlaprevir is a potent inhibitor of the HCV nonstructural protein 3 (NS3) serine protease, which is necessary for viral replication. It is primarily metabolized by the cytochrome P450 3A4 pathway, making its exposure subject to rapid hepatic clearance. Ritonavir is co-administered as a pharmacokinetic enhancer: by potently inhibiting CYP3A4, ritonavir slows the metabolism of narlaprevir, elevating and prolonging narlaprevir plasma concentrations. The combination has demonstrated a robust suppression of HCV viral load and was tested both as monotherapy and with pegylated interferon-alpha-2b in HCV genotype 1-infected treatment-naïve and experienced adults.