What is the composition of Bactrim?

Bactrim is a combination antibiotic that consists of sulfamethoxazole and trimethoprim. This pairing works synergistically to inhibit bacterial folic acid synthesis, making it effective against a variety of bacterial infections. Sulfamethoxazole, a sulfonamide, acts as a competitive inhibitor of para-aminobenzoic acid (PABA), which is necessary for the production of folate in bacteria. Trimethoprim, on the other hand, inhibits dihydrofolate reductase, an enzyme further down the line in the folate synthesis pathway. This dual action enhances the antibacterial efficacy compared to using either drug alone.

Other combinations provided in the options comprise different classes of antibiotics that do not reflect the composition of Bactrim. Understanding the components of Bactrim is crucial for recognizing its therapeutic uses and potential bacterial resistance profiles.