Grazoprevir potassium salt is primarily used in the treatment of chronic hepatitis C virus (HCV) infections. It functions as a potent inhibitor of the HCV NS3/4A protease, an enzyme essential for viral replication. By blocking this enzyme, it effectively reduces the viral load in patients. It is often combined with other antiviral agents, such as elbasvir, in fixed-dose combination therapies to enhance efficacy and prevent resistance. This combination therapy is particularly effective against multiple HCV genotypes, offering a broad-spectrum treatment option. Its use has significantly improved cure rates for HCV-infected patients, providing a well-tolerated and effective therapeutic solution. Additionally, it is a key component in regimens for patients with comorbid conditions, such as HIV coinfection or advanced liver disease.