The results of a targeted pharmacy intervention program.

Increasing resistance to ceftazidime and some other beta-lactam antibiotics developed among Enterobacter species after use of ceftazidime increased at a 500-bed community teaching hospital. Severe restrictions on the use of ceftazidime were imposed by pharmacy intervention. For empiric therapy of severe infections, a combination of tobramycin plus piperacillin was most frequently substituted for ceftazidime. Susceptibility patterns of Enterobacter returned to baseline within 3 months after active intervention reduced use of ceftazidime by 98% of its peak. There was no development of enhanced resistance to tobramycin or piperacillin or to other antibiotics on the formulary. It is concluded that active pharmacy intervention resulted in reversion of susceptibility of Enterobacter species to baseline for ceftazidime and the other beta-lactam antibiotics (ie, aztreonam, cefotaxime, ceftriaxone, mezlocillin, and piperacillin) for which covariance (ie, parallel decline of organisms' sensitivities) or cross-resistance had developed.