Abstract

The hemolytic anemia-producing properties of sulfapyridine, sulfamerazine and sulfadiazine have been evaluated in mice by determining the percentage incidence of anemia produced by various concentrations of sulfonamide in the blood. The concentration of sulfonamide in the blood necessary to produce a 50 per cent incidence of anemia was found to be: with sulfapyridine, 2.8 mgm., with sulfadiazine, 33.0 mgm., and with sulfamerazine, 31.0 mgm. per 100 cc. Although a high micromolar concentration of sulfonamide within the erythrocytes was required to produce anemia with sulfadiazine and sulfamerazine, sulfapyridine produced the same incidence of anemia with an erythrocytic concentration only about one-tenth as great. The possible clinical significance of these findings is discussed.