SULFADIAZINE

also spelled Sulphadiazine, synthetic drug belonging to the sulfonamide group and used in medicine to treat microbial infections, particularly those involving the urinary and gastrointestinal tracts. Since its introduction into medicine in the early 1940s, sulfadiazine has become the most widely used sulfonamide drug; it has few side effects and a broad spectrum of activity. Sulfadiazine is administered orally or by intravenous injection, either alone or in combination with other drugs. A commonly used preparation combining sulfadiazine with two closely related sulfonamides, sulfamerazine and sulfamethazine, is trisulfapyrimidines (triple sulfas). The use of such mixtures of sulfonamides reduces the incidence of side effects, which include loss of appetite, nausea, and skin rashes.