Factors contributing to ribavirin dose reduction due to anemia during interferon alfa2b and ribavirin combination therapy for chronic hepatitis C.

Background: Recent studies indicate that combination therapy with ribavirin and interferon alfa2b (IFNAlpha2b) is effective for chronic hepatitis C virus (HCV) infection. However, reversible hemolytic anemia is a common side effect of this therapy.
Methods: We determined those factors that contribute to ribavirin dose reduction due to anemia during this treatment by using multiple logistic regression analysis in Japanese patients. The study included 123 patients with chronic hepatitis C (85 male, 38 female; mean age, 50 years; range, 20-70 years), who received 24-week combination therapy. All patients were treated with IFNAlpha2b daily for 2 weeks, followed by three times weekly dosing for 22 weeks, with oral ribavirin twice daily, at a total daily dose of 600 or 800 mg.
Results: Of the 123 patients, 34 patients required dose reduction of ribavirin, and 78 patients required no dose reduction. Overall, 20 patients discontinued. On univariate analysis, reduction of the ribavirin dose correlated significantly with pretreatment hemoglobin (Hb) levels of less than 14 g/dl, female sex, and patient age 55 years or older. On multivariate analysis, pretreatment Hb of less than 14 g/dl level and age 55 years or older were significantly associated with ribavirin dose reduction. The hazard ratios were 3.56 (95% confidence interval [CI], 1.48-8.53) for pretreatment Hb levels of less than 14 g/dl, and 2.50 (95% CI, 1.05-5.94) for age 55 years or more.
Conclusions: Because patient age of 55 years or more, and Hb levels of less than 14 g/dl are significant factors that influence ribavirin-induced hemolytic anemia, more careful monitoring is necessary during combination therapy for patients with these risk factors.