The influence of Norakin on the reproduction of influenza A and B viruses.

The action of the anticholinergic drug Norakin (triperiden) on the reproduction of influenza virus A and B strains was studied. In cell culture, primary transcription of influenza A/FPV/Weybridge and of influenza B/Japan/73 is strongly inhibited by Norakin (20 micrograms/ml). When present simultaneously, Norakin and rimantadine exert an additive effect. Rimantadine-resistant mutants of influenza A exhibit a definite, though limited, cross-resistance to Norakin, and vice versa. The results indicate that Norakin blocks early stages of the infectious cycle and that the modes of antiviral action of Norakin and rimantadine are not identical.