Background and Aim: Interferon and ribavirin combination therapy for chronic hepatitis C produces hemolytic anemia. This study was conducted to identify the factors contributing to ribavirin-induced anemia.
Methods: Eighty-eight patients with chronic hepatitis C who received interferon-α-2b at a dose of 6 MU administered intramuscularly for 24 weeks in combination with ribavirin administered orally at a dose of 600 mg or 800 mg participated in the study. A hemoglobin concentration of <10 g/dL was defined as ribavirin-induced anemia.
Results: Ribavirin-induced anemia occurred in 18 (20.5%) patients during treatment. A 2 g/dL decrease in hemoglobin concentrations in patients with anemia was observed at week 2 after the start of treatment. The hemoglobin concentration in patients with ≥2 g/dL decrease at week 2 was observed to be significantly lower even after week 2 than in patients with <2 g/dL decrease (P < 0.01). A significant relationship was observed between the rate of reduction of hemoglobin concentrations at week 2 and the severity of anemia (P < 0.01). Such factors as sex (female), age (≥60 years old), and the ribavirin dose by body weight (12 mg/kg or more) were significant by univariate analysis.
Conclusions: Careful administration is necessary in patients ≥60 years old, in female patients, and in patients receiving a ribavirin dose of 12 mg/kg or more. Patients who experience a fall in hemoglobin concentrations of 2 g/dL or more at week 2 after the start of treatment should be monitored with particular care.