Sulfadimidine or sulfamethazine is a sulfonamide antibacterial. Sulfadimidine or sulfamethazine is a sulfonamide antibacterial. There are non-standardizeda abbreviations for it as 'sulfadimidine' (abbreviated SDI and more commonly but less reliablyb SDD) and as 'sulfamethazine' (abbreviated SMT and more commonly but less reliablyc SMZ). Other names include sulfadimerazine, sulfadimezine, and sulphadimethylpyrimidine. In Pakistan, it is available with the brand name of 'Sanadine-33.3 %' as potential treatment of E-coli enteritis in veterinary medicine.