Asunaprevir is used in the treatment of chronic hepatitis C virus (HCV) infection, specifically genotype 1. It functions as a potent inhibitor of the HCV NS3/4A protease, an enzyme essential for viral replication. By blocking this enzyme, Asunaprevir prevents the virus from multiplying, thereby reducing viral load in patients. It is typically administered in combination with other antiviral agents, such as daclatasvir, to increase efficacy and reduce the risk of resistance. This combination therapy offers a non-interferon treatment option, which improves tolerability and patient compliance. Asunaprevir-based regimens are particularly beneficial for patients who cannot tolerate interferon-based therapies due to side effects or underlying health conditions.