Urinary tract infections: the efficacy of trimethoprim/sulfamethoxazole

The diagnosis of bacterial urinary infections is reasonably exact and routine in medical practice. In contrast, therapeutic regimens have been arbitrary with little rationale and no relationship to infection site or therapeutic objective. During the past decades a series of careful prospective studies have carefully characterized episodes of infection to the site within the urinary tract, and adequate follow-up has been obtained to determine the pattern of response. This has led to the emergence of definite guidelines on dose and duration for antimicrobial therapy. The antimicrobial combination of trimethoprim and sulfamethoxazole has been employed in many of these studies and has been found to be a particularly effective agent for both the treatment and prevention of urinary infections. These studies and their implications for optimal treatment of urinary infections are reviewed.