The
antiviral efficacy of
amantadine in patients with
chronic hepatitis C is controversial. In this randomized, prospective, placebo-controlled, multicenter trial, triple
therapy with
interferon alfa (IFN-alpha)-2a plus
ribavirin and
amantadine (
amantadine group) was compared with combination
therapy IFN-alpha plus
ribavirin (control group). Four hundred previously untreated patients with histologically proven
chronic hepatitis C were randomly allocated to treatment with
amantadine sulphate (100 mg twice daily orally) or a matched placebo together with IFN-alpha induction plus
ribavirin (1,000-1,200 mg/day orally) for 48 weeks. The primary end point was sustained virologic response (SVR) defined as undetectable serum hepatitis C virus (HCV)
RNA (<100 copies/mL) 24 weeks after the end of treatment. SVR was observed in 52% of the
amantadine group and in 43.5% of the control group (
P =.11). Among patients with HCV genotype 1
infection, the corresponding SVR rates were 39% and 31%, respectively. The virologic on-treatment response rate in week 24 was significantly higher in the
amantadine group as compared with the control group (70% vs. 59%, respectively, P =.016). This beneficial effect was mainly related to HCV type 1-infected patients (63% vs. 47%, respectively, P =.012). Independent factors associated with SVR, according to multiple logistic regression analysis, were
amantadine treatment, low baseline HCV
RNA, platelet counts (>/=250/nL), pretreatment ALT quotient >/=3, and GGT level (<28 U/L) as well as HCV genotypes other than 1. In conclusion, although we could not demonstrate a significant advantage of the triple regimen in univariate analysis, multivariate analysis offers arguments that
amantadine should be considered as a potential anti-HCV
drug in future studies.