Trimethoprim-Sulfamethoxazole

Folate Antagonist

Drug Class: Folate Antagonist
Mechanism of Action (MOA): Sequential folate-synthesis blockade (sulfamethoxazole → dihydropteroate synthase; trimethoprim → dihydrofolate reductase).
Clinical Notes: UTIs, PCP prophylaxis/treatment; community MRSA use is off-label; hyperkalemia; avoid in sulfa allergy & pregnancy.
Source: FDA label

Sources

Reviewed September 2026

FDA label — FDA / DailyMed

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Used for

Cellulitis · Infectious Disease
HIV / AIDS · Infectious Disease
UTI / Pyelonephritis · Genitourinary

Same family

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