Protective Effect of Sulfapyridine, Sodium Sulfapyridine, and Sulfanilamide in Pneumococcus Infection Types I, II, and III

1. Sulfapyridine administered orally to rabbits is slightly less toxic than sulfanilamide. 2. Sodium sulfapyridine given intravenously is considerably more toxic than sodium sulfanilamide. 3. While the protective effect of sulfapyridine in pneumococcal bacteremia types I, II, and III is small, 20 to 30% of mice surviving on the 4th day and less than 10% on the 7th day, it is somewhat higher than that afforded by sulfanilamide, which results in an average survival of 2 to 3 days. Sulfapyridine prolongs life of infected mice only for an additional period of 2 to 4 days. The protective effect of sodium sulfapyridine is of the same order as that of sulfapyridine.