BACKGROUND/AIMS: The benefit of amantadine combination therapy, either with interferon (IFN) alone (double therapy) or with ribavirin and IFN (triple therapy) is unknown.
METHODS: We analyzed the effect of amantadine on the end-of-treatment virological response and the sustained response using meta-analysis of 31 randomized controlled trials.
RESULTS: Overall analysis revealed a significant effect of amantadine. Triple therapy was the best regimen for improving the sustained response (mean difference: 8.4%, 95% CI: 2.4-13.8%, P=0.002). In subgroup analysis, amantadine did not have a significant effect upon naive patients or relapsers. In non-responders, combination therapy with amantadine was associated with a significant effect on the sustained response (mean difference: 8.3%, 95% CI: 1.9-14.6%, P=0.01). In sensitivity analysis, double therapy did not improve virological responses. Conversely, triple therapy tended to improve the end-of-treatment virological response and was associated with a significant effect upon the sustained response (mean difference: 12.7%, 95% CI: 3.8-21.6%, P=0.005).
CONCLUSIONS: Combination therapy with amantadine is of no effect upon naive patients or relapsers. In non-responders, triple therapy with amantadine improved the sustained response. New randomized controlled trials are required to confirm this meta-analysis.