Trimethoprim
![Structural formula of trimethoprim](/Images/godic/202502/04/Trimethoprim.svg2444.png")
![Ball-and-stick model of the trimethoprim molecule](/Images/godic/202502/04/Trimethoprim-from-hydrochloride-xtal-1984-3D-balls2444.png")
![Tetrahydrofolate synthesis pathway](/Images/godic/202502/04/THFsynthesispathway2445.png")
![Staphylococcus aureus DHFR in complex with NADPH and trimethoprim PDB entry 2W9G [23]](/Images/godic/202502/04/Wild-type_staphylococcus_aureus_DHFR_in_complex_with_NADPH_and_trimethoprim2445.gif")
Trimethoprim (TMP) is an antibiotic used mainly in the treatment of bladder infections. Other uses include for middle ear infections and travelers' diarrhea. With sulfamethoxazole or dapsone it may be used for Pneumocystis pneumonia in people with HIV/AIDS. It is taken by mouth.