Biological Activity
Sulfamethazine is an antimicrobial sulfur drug th at blocks the synthesis of dihydrofolic acid by inhibiting the enzyme dihydropteroate synthase. Sulfamethazine is a competitive inhibitor of bacterial para-aminobenzoic acid (PABA), which is required for bacterial synthesis of folic acid. It induces CYP3A4 expression and is acetylated by N-acetyltransferase. It exhibits sex dependent pharmacokinetics, metabolized by the male specific isoform CYP2C11. Sulfamethazine is bacteriostatic.
