Antiviral action of dipyridamole and its derivatives against influenza virus A

Dipyridamole proved to be active against influenza viruses A/England 42/72, A/Bangkok 1/79 and A/fowl plague (FPV). The antiviral activities assayed by various methods varied from 90-99 per cent. No inhibition was found against influenza virus B/Leningrad 235/74 in vitro. Three dipyridamole derivatives were significantly active in tissue cultures against influenza virus A/England 42/72 and A/FPV. In white mice infected with influenza virus A/England 42/72 dipyridamole administered orally showed a protection rate of 62.5 per cent.