Common Brands Bactrim, Septra, Bactrim DS, Septra DS, Sulfatrim Pediatric
Drug Class
Sulfonamide antibiotic
Controlled Substance Classification
Not a controlled medication
Generic Status
Lower-cost generic available
Prescription only
Daisy Chau, PharmD
Daisy Chau, PharmD
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Medically reviewed by Daisy Chau, PharmD last update on 20/12/2023


Bactrim, a brand name for the combination of sulfamethoxazole and trimethoprim, is an antibiotic medication known for its effectiveness against a broad range of bacterial infections. Introduced in the late 1960s, Bactrim was a significant advancement in the field of antibiotics, offering a potent solution against bacteria resistant to other antibiotics. 

Its two active ingredients, sulfamethoxazole and trimethoprim, work in tandem, inhibiting successive steps in the bacterial biosynthesis of essential nucleic acids and proteins.

Sulfamethoxazole, belonging to the sulfonamide drug class, was discovered in the 1930s and showed remarkable antibacterial properties. Trimethoprim, developed later, enhanced the efficacy of sulfamethoxazole by blocking a different enzyme in the bacterial pathway. 

This synergistic combination results in a higher antibacterial activity compared to either drug alone. Bactrim is particularly effective against infections of the urinary tract, respiratory system, gastrointestinal tract, and certain types of pneumonia, making it a versatile choice in combating bacterial infections.



Prescription only

Pregnancy & Lactation