Sulfamethazine is a sulfa drug used like sulfadiazine and also in veterinary medicine to treat a variety of infections. It is an antibacterial agent. Sulfonamides has been widely used in the treatment and prevention of infections such as urinary tract infections, chlamydia, rheumatic fever, toxoplasmosis and malaria. The development of resistance in many of these organisms has greatly limited the clinical usefulness of these drugs.