Does bactrim (sulfamethoxazole and trimethoprim) have sulfa. i am allergic to sulfa? which one is better for uti keflex or bactrim (sulfamethoxazole and trimethoprim)

Bactrim (sulfamethoxazole and trimethoprim) is sulfa: Bactrim (sulfamethoxazole and trimethoprim) contains a sulfonamide ("sulfa drug") called sulfamethoxazole. It needs to be avoided by people with sulfa allergy. Cephalexin (Keflex) is less reliable for UTI; many UTI bacteria are resistant to it. Ask your doctor about possible treatment with a quinolone like ciprofloxacin, levofloxacin, and others.