trimethoprim, Trimpex (Discontinued Brand), Proloprim (Discontinued Brand), Primsol

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GENERIC NAME: trimethoprim

BRAND NAMES: Primsol

DISCONTINUED BRANDS: Trimpex, Proloprim

DRUG CLASS AND MECHANISM: Trimethoprim is a synthetic (man-made) antibiotic that interferes with the production of tetrahydrofolic acid, a chemical that is necessary in order for bacteria and human cells to produce proteins. Trimethoprim inhibits production of tetrahydrofolic acid by inhibiting the enzyme responsible for making tetrahydrofolic acid from dihydrofolic acid. Trimethoprim inhibits the bacterial enzyme more than the human enzyme. Therefore, trimethoprim has less effect on the production of tetrahydrofolic acid by humans. Because of the frequent development of resistance to trimethoprim, it is more effective when combined with another antibiotic, sulfamethoxazole (Azo-Gantanol), and is rarely used alone. Trimethoprim was first approved by the FDA in combination with sulfamethoxazole (for example, Bactrim, Septra) in 1973. It was approved as a stand-alone drug in 1980.

PRESCRIBED FOR: Trimethoprim is used for the treatment of uncomplicated urinary tract infections due to susceptible bacteria.

SIDE EFFECTS: The most common side effects associated with trimethoprim are gastrointestinal, such as:

Medically Reviewed by a Doctor on 1/28/2015



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