What class is bactrim (sulfamethoxazole and trimethoprim) ds?

2 classes: Bactrim (sulfamethoxazole and trimethoprim) is a combination of 2 drugs, trimetoprim and sulfamethoxazole. The first is a pyrimidine derivative and the second is a sulfonamide (sulfa). Ds stands for double strength as opposed to ss, single strength. The difference is in the dosage.

Combo: This is the commercial name for trimethoprim/sulfamethoxazole. The class of antibiotics is sulfonamide antibiotic combination.