Used primarily as an antibacterial agent, especially in the treatment of urinary tract infections. It works by inhibiting bacterial growth through interference with folic acid synthesis, which is essential for DNA and cell division in bacteria. Commonly prescribed in combination with other sulfonamides or antibiotics to enhance effectiveness and reduce resistance development. Also found application in treating respiratory infections, otitis media in children, and certain types of chronic bronchitis when caused by susceptible organisms. Due to its solubility properties, it helps reduce the risk of crystalluria compared to older sulfonamides, making it a safer option for long-term therapy.