sulfamethoxazole + trimethoprim (GSK)

Co-trimoxazole is a fixed-dose antibacterial combination of **sulfamethoxazole**, a sulfonamide that inhibits bacterial dihydropteroate synthase, and **trimethoprim**, an inhibitor of bacterial dihydrofolate reductase. The sequential inhibition of microbial folate synthesis produces synergistic antimicrobial activity. It is administered orally or intravenously and is used for susceptible bacterial infections and for treatment or prophylaxis of *Pneumocystis jirovecii* pneumonia. A randomized Khon Kaen University study is evaluating 12 versus 20 weeks of oral eradication therapy for relapse prevention in culture-confirmed melioidosis. ([accessdata.fda.gov](https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/018374s029lbl.pdf))

Brand names

BactrimBactrim DSBactrim PediatricBethaprimBethaprim PediatricCotrimCotrim DSCotrim PediatricSeptraSeptra DSSeptra IVSeptrinSeptrin ForteSeptranSulfatrimSulfatrim PediatricUroplusUroplus DS

Other names

co-trimoxazolecotrimoxazoleSMX-TMPSMZ-TMPsulfamethoxazole + trimethoprimsulfamethoxazole-trimethoprimsulfamethoxazole/trimethoprimSXTTMP-SMXTMP-SMZtrimethoprim + sulfamethoxazoletrimethoprim-sulfamethoxazole