Effect of selenazofurin on influenza A and B virus infections of mice.

The inhibitory effects of selenazofurin and ribavirin on influenza A and B virus infections in mice were compared. Both compounds, when administered intraperitoneally (i.p.), reduced lung consolidation and prolonged mean day of death, but ribavirin more effectively increased survivor number and lowered lung viral hemagglutinin (HA) titers. Lung HA titers often increased in selenazofurin-treated animals. To determine the most appropriate i.p. treatment schedule, influenza A virus-infected mice were treated once, twice or thrice daily for 7-9 days, or once only. Treatment once daily for 9 days beginning 4 h pre-virus exposure, for 3 days beginning 24 h post-virus exposure, or once only 48 h post-virus exposure was most effective. Body temperature, which usually declined during infection, increased to near-normal levels in animals treated with selenazofurin, especially in animals treated a single time or for 3 days with high dose levels. Selenazofurin was well tolerated at a dose of 50 mg/kg administered twice daily, and at 400 mg/kg administered once only. Rectal temperatures temporarily declined following every other day treatment with 400 mg/kg.