Prophylactic use of antimicrobial agents.

A major shortcoming in many studies of prophylactic antimicrobial agents has been lack of adequate evaluation of potential advantages and disadvantages in prospective double-blind investigations. Recent data demonstrated that certain bowel preparations given orally and antimicrobial agents applied topically or given parenterally prevent postoperative infections. Several studies have shown that if topically and parenterally administered antimicrobial agents are used, they should be given only during the surgical procedure. Antimicrobial therapy initiated after an operation is generally not indicated for prophylaxis and, in fact, increases the potential disadvantages of prophylaxis. There is no evidence that combinations of orally, topically, and parenterally administered antimicrobial agents reduce infection rates below those achieved by the use of any one route of prophylactic antimicrobial administration.