Sulfonamide Antibiotics
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Overview
One of the oldest classes of antibiotics, sulfonamides are synthetic antimicrobial agents effective against a broad range of gram-positive and gram-negative bacteria. Combination products like trimethoprim-sulfamethoxazole are among the most widely used antibiotics globally.
How do sulfonamide antibiotics work?
Sulfonamides are structural analogs of para-aminobenzoic acid (PABA) and competitively inhibit the enzyme dihydropteroate synthase in the folic acid synthesis pathway. When combined with trimethoprim, which inhibits dihydrofolate reductase (a later step in the same pathway), the combination produces sequential blockade of folate synthesis, resulting in synergistic bactericidal activity.
Drugs in this class
- Trimethoprim-Sulfamethoxazole (Bactrim, Bactrim DS, Septra, Septra DS, Sulfatrim)