Effective administration methods and dosages of interferon therapy for chronic hepatitis C

The efficacy of interferon alfa (IFN-alpha) was evaluated in 127 hepatitis C virus-ribonucleic acid (HCV-RNA)-positive patients with chronic hepatitis C in relation to HCV-RNA levels and genotype. Patients were assigned to one of three groups. Patients in group A received IFN-alpha daily for 8 weeks (total dose, 336 million units [MU]); patients in group B received IFN-alpha daily for 4 weeks and then intermittently for 20 weeks (total dose, 348 MU); and patients in group C received IFN-alpha daily for 2 weeks and then intermittently for 22 weeks (total dose, 480 MU). Complete response rates in groups B and C were significantly higher than those in group A, regardless of the virus level or genotype. Complete response rates in groups B and C were similar, but in patients with a high virus level or HCV-RNA genotype II, the partial response rate in group C was significantly higher than that in group B. In conclusion, IFN-alpha was more effective after daily and then intermittent administration than after daily administration only, and a higher daily dose was necessary to be more effective in patients with high virus levels or HCV-RNA genotype II.