The invention is directed to a method of treating infections by hepatitis C virus by administeringN-{3-[(1R,2S,7R,8S)-3-(4-fluoro-benzyl)-6-hydroxy-4-oxo-3-aza-tricyclo[6.2.1.02,7]undec-5-en-5-yl]-1,1-dioxo-1,4-dihydro-1λ6-benzo[1,2,4]thiadiazin-7-yl}-methanesulfonamide and one or more additional antiviral compounds or pharmaceutical compositions containing such compounds.本發明關於一種治療C型肝炎病毒感染之方法,其經由投與N-{3-[(1R,2S,7R,8S)-3-(4-氟-苯甲基)-6-羥基-4-酮基-3-氮雜-三環[6.2.1.02,7]十一-5-烯-5-基]-1,1-二酮基-1,4-二氫-1λ6-苯并[1,2,4]噻二-7-基}-甲磺醯胺及一或多種其他抗病毒化合物或含此化合物之醫藥組成物。