Ribavirin considerations in treatment optimization.

Ribavirin is a guanosine analogue that has little antiviral activity when used alone, but considerably enhances the efficacy of conventional and pegylated interferon in the treatment of hepatitis C virus (HCV). The precise mode of action of ribavirin is not fully understood; however, it is crucial for the achievement of high sustained virological response (SVR) rates by enhancing virological response and reducing relapse rates. Data from several studies have confirmed that higher initial doses of ribavirin lead to higher SVR rates. Furthermore, intensified ribavirin dosing might also improve SVR rates in 'difficult-to-cure' patients. It is also important to minimize ribavirin dose reductions to promote high SVR rates and to maintain ribavirin levels throughout treatment to prevent viral breakthrough and relapse. The pharmacokinetic profile of ribavirin reveals a long elimination half-life due to accumulation in the blood, such that its side-effect profile includes haemolytic anaemia. Therefore, finding the optimal ribavirin dose requires a balance between efficacy and its associated side effects to ensure improved patient outcomes. Here, we discuss how optimizing the ribavirin component of combined therapy for HCV is an essential part of treatment optimization.