Bactrim is used to treat ear infections, urinary tract infections, bronchitis, traveler’s diarrhea, and Pneumocystis carinii pneumonia. Bactrim is an antibiotic combination containing a sulfonamide antibiotic. It works by killing sensitive bacteria. Generic name is Sulfamethoxazole/Trimethoprim tablets (sul-fa-meth-OX-a-zole/trye-METH-oh-prim), brand name is...