Used primarily to treat urinary tract infections due to its effectiveness against common bacterial pathogens in the urinary system. It works by inhibiting bacterial synthesis of folic acid, which is essential for bacterial growth. Often prescribed for short-term therapy in mild to moderate infections, especially those caused by susceptible strains of E. coli and Proteus organisms. Its use has declined over time due to the availability of newer antibiotics with better safety profiles, but it may still be found in some regions for specific clinical cases.