Widely used in combination with trimethoprim (as co-trimoxazole), this chemical is effective against a broad range of bacterial infections. It is commonly prescribed for urinary tract infections, respiratory tract infections such as bronchitis and pneumonia, and ear infections. It also treats traveler’s diarrhea caused by susceptible strains of E. coli. In immunocompromised patients, including those with HIV, it helps prevent and treat Pneumocystis jirovecii pneumonia. Additionally, it is used in managing certain types of skin and soft tissue infections. Its broad-spectrum activity and oral bioavailability make it a valuable option in both outpatient and long-term prophylactic settings.