Cotrimoxazole - does it contain penicillin?

4 Jan 2011

No, Co-trimoxazole does not contain penicillin. It contains sulfamethoxazole and trimethoprim. Sulfamethoxazole and trimethoprim are both antibiotics that treat different types of infection caused by bacteria.

Sulfamethoxazole inhibits bacterial synthesis of dihydrofolic acid by competing with PABA.

Trimethoprim blocks production of tetrahydrofolic acid by inhibiting the enzyme dihydrofolate reductase. This combination blocks 2 consecutive steps in bacterial biosynthesis of essential nucleic acids and proteins and is usually bactericidal.

The combination of sulfamethoxazole and trimethoprim is used to treat ear infections, urinary tract infections, bronchitis, traveler's diarrhea, and Pneumocystis carinii pneumonia.

Co-trimoxazole is considered safe in patients with penicillin allergy ... but still treat with caution.

http://www.drugs.com/mtm/sulfamethoxazole-and-trimethoprim.html