Impact of a hospital-wide antimicrobial formulary intervention on the incidence of multidrug-resistant gram-negative bacteria.

We examined the impact of an antimicrobial formulary change, based on reduction in third-generation cephalosporin use, on resistant gram-negative pathogens in a tertiary hospital. No significant changes were demonstrated in their incidence per 1000 patient-days. Otherwise, there was a significant decrease in rate of extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae (63.