Ribavirin Dose Optimization for the Treatment of Hepatitis C

Inclusion Criteria: * Age \> 18 years * Chronic hepatitis C and failure of prior treatment with peginterferon plus ribavirin (non-response: HCV-RNA decreased less than 2 logs after 3 months of treatment; relapse: HCV-RNA that becomes positive again after treatment is stopped * Compensated hepatic disease (Child-Pugh ≤ 6) * Provision by patient of his or her written consent Exclusion Criteria: * Females who are pregnant or lactating will be excluded * Renal failure (estimated glomerular filtration rate \< 50 ml/min) * A contraindication to treatment with peginterferon plus ribavirin (uncontrolled psychiatric illness, pregnancy/nursing/non-use of effective contraceptive method, uncontrolled epilepsy for at least 6 months, heart failure, unstable angina, hemoglobin \< 120 g/L, neutrophils \< 1,000/mm3, platelets \< 50 x 109/L, or any other condition that, in the investigator's opinion, contraindicates use of the treatment)