- An antimicrobial agent that potentiates the effect of sulfonamides and sulfones; usually used in combination with sulfamethoxazole.
* * *tri·meth·o·prim trī-'meth-ə-.prim n a synthetic antibacterial drug C14H18N4O3 used alone esp. to treat urinary tract infections and Pneumocystis carinii pneumonia and in combination with sulfamethoxazole to treat these as well as other infections (as shigellosis or acute otitis media) see BACTRIM
* * *n.an antibacterial drug that is active against a range of microorganisms; taken by mouth or injection, it is used mainly in the treatment of chronic urinary-tract infections and respiratory-tract infections. Long-term treatment may cause anaemia due to deficiency of folic acid, with which the drug interacts. Trimethoprim has been administered in a combined preparation with sulfamethoxazole (see co-trimoxazole) but is now more usually prescribed alone, because of the severity of the side-effects of co-trimoxazole. Trade names: Monotrim, Trimopan.
* * *tri·meth·o·prim (tri-methґo-prim) [USP] an antibacterial closely related to the antimalarial pyrimethamine, acting by inhibiting a step in bacterial folate biosynthesis and effective against various gram-negative and gram-positive bacteria; administered orally in the prophylaxis and treatment of urinary tract infections and the treatment of pneumocystis pneumonia. It is usually administered in combination with a sulfonamide because the two drugs markedly potentiate each other, and in such combination (e.g., co-trimoxazole) has additional uses including treatment of bronchitis, Shigella enterocolitis, acute otitis media, and traveler's diarrhea. In certain countries, it is used alone as an antimalarial.
Medical dictionary. 2011.