Sulfamethoxazole is an isoxazole (1,2-oxazole) compound having a methyl substituent at the 5-position and a 4-aminobenzenesulfonamido group at the 3-position. It has a role as an antimicrobial agent, an antibacterial agent, an antiinfective agent, a xenobiotic, a P450 inhibitor, an EC 2.5.1.15 (dihydropteroate synthase) inhibitor, an epitope, an EC 1.1.1.153 [sepiapterin reductase (L-erythro-7,8-dihydrobiopterin forming)] inhibitor, an environmental contaminant and a drug allergen. It is a sulfonamide, a substituted aniline, a member of isoxazoles and a sulfonamide antibiotic. It is functionally related to a sulfanilamide.
