Taribavirin

Although injection drug users (IDUs) account for over 70% of new cases of HCV infection/year, there is no consensus on how to approach their medical care. In some Canadian centres, patients must be free of recreational drug use for as long as 6 months before being considered for HCV therapy. This is not consistent with current North American guidelines. Over the past 5 years, we have developed a successful program for the treatment of HIV infection in this population, based on a multi-disciplinary comprehensive program including directly observed therapy (DOT). Even though the duration of therapy for HCV is shorter than for HIV (as little as 6 months vs. life-long), we must address issues of administration of a weekly injection (interferon), twice daily pills (ribavirin) and the risk of significant side effects (including anxiety and depression) to successfully expand our program to treat this disease. Further, it may be that even if the program is successful, its benefits will be negated by HCV re-infection due to continued risk behaviors for its transmission.

The objective of the study is to select an optimal dose of taribavirin by comparing the efficacy and safety of 3 taribavirin dose levels, 20, 25, and 30 mg/kg/day, versus ribavirin 800 to 1400 mg/day based on body weight, both administered in combination with peginterferon alfa-2b to therapy-naive patients with chronic Hepatitis C Virus (HCV) genotype 1 infection.