 Increased RBV dosage has been considered a contributory factor to the better efficacy in treating refractory genotype HCV. For example, recent studies suggested that using RBV 800 mg daily is adequate to treat HCV genotype non-1 while the standard dosage of RBV is required to treat HCV genotype 1 NIH 2002. The investigators thus propose to use RBV 1000-1200 mg daily according to the body weight of the patient. 