Taribavirin in the treatment of hepatitis C

Treatment of chronic hepatitis C virus (HCV) is limited by substantial side effects including ribavirin-induced hemolytic anemia. Taribavirin, a ribavirin prodrug, was designed to concentrate within the liver to target HCV-infected hepatocytes while minimizing distribution within red blood cells (RBCs) and the subsequent development of hemolytic anemia.

The objective of the review is to evaluate the efficacy and safety of taribavirin as compared with ribavirin in the treatment of chronic HCV infections. A PubMed search was performed using the following key words: viramidine, taribavirin and ribavirin analog. Additional sources included press releases on preliminary results of clinical trials of taribavirin and abstracts presented at international meetings. The literature suggests that weight-based dosing of taribavirin at 25 mg/kg demonstrates lower rates of hemolytic anemia with comparable rates of sustained virologic response (SVR) and is the optimum dose for further studies comparing the efficacy of taribavirin with weight-based dosing of ribavirin.

Failure to eradicate HCV may be associated with extrahepatic viral replication. The dosing strategy of taribavirin favors concentration within the liver to reduce treatment-limiting rates of anemia but may be insufficient to prevent virologic relapse.