Sulfamethoxazole is a sulfonamide antibiotic. It is most often used as part of a synergistic combination with trimethoprim in a 5:1 ratio in co-trimoxazole.

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... SULFAMETHOXAZOLE (Gantanol®) is a sulfonamide antibiotic. Sulfamethoxazole stops the growth of certain bacteria. It treats urinary tract infections and some other infections. Generic sulfamethoxazole tablets are available. ...
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Sulfamethoxazole Systematic (IUPAC) name 4-amino-N-(5-methylisoxa ...
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