Taribavirin in the treatment of hepatitis C.

INTRODUCTION: 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. AREAS COVERED: 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. EXPERT OPINION: 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.