Decreased antimicrobial resistance following changes in antibiotic use.

The widespread use of perioperative antibiotic prophylaxis makes surgical procedures an important component of overall antibiotic use. Attempts to reduce costs and limit the emergence of resistance among pathogenic bacteria by altering antibiotic use must therefore encompass surgical prophylaxis. Several recent reports have linked the use of third-generation cephalosporins with beta-lactam resistance in gram-negative bacteria and with vancomycin resistance in Enterococcus. Fortunately, susceptibility can often be restored by replacing third-generation cephalosporins with drugs that are less likely to foster resistance; a penicillin/beta-lactamase inhibitor combination is often a suitable substitute. An antibiotic resistance management program can effect the type of changes in antimicrobial use necessary to forestall or reverse an outbreak of resistant pathogens. Such a plan was implemented at Methodist Hospital, Indianapolis, Indiana, in 1995. Piperacillin/tazobactam (in combination with an aminoglycoside) was added to the formulary, primarily as empiric therapy, replacing the use of third-generation cephalosporins such as ceftazidime. Following this change, the prevalences of vancomycin-resistant Enterococcus, methicillin-resistant Staphylococcus aureus, and other resistant gram-negative bacilli were all reduced. As this effective formulary change shows, appropriate changes in antibiotic drug, dosage, and administration route can limit the emergence of resistance and ultimately lower costs.