| Title | Introduction of ertapenem onto a hospital formulary: Effect on antimicrobial usage and improved in vitro susceptibility of Pseudomonas aeruginosa. | | Author(s) | Goldstein EJ, Citron DM, Peraino V, Elgourt T, Meibohm AR, Lu S | | Institution | RM Alden Research Laboratory, Santa Monica, CA; and the Departments of Infectious Diseases, Microbiology and Pharmacy, St. Johns' Health Center, Santa Monica, CA 90404; and Merck & Co Inc., North Wales, PA. | | Source | Antimicrob Agents Chemother 2009 Sep 28. | | Abstract | After ertapenem was added to the formulary of a 344-bed community teaching hospital, we retrospectively studied its effect on antimicrobial utilization and on the in vitro susceptibility of various antimicrobial agents against Pseudomonas aeruginosa. Three study periods were defined as pre-introduction (months 1-9), post-introduction but before auto-substitution of ertapenem for ampicillin-sulbactam (months 10-18) and after the policy of auto-substitution (months 19-48) was initiated. Ertapenem usage rose slowly from introduction to a range of 36-48 defined daily doses/1,000 patient days (DDD) with a resultant decrease in ampicillin-sulbactam usage due to auto-substitution. Imipenem usage peaked 6 months after the introduction of ertapenem and started to decline coincident with increased use of ertapenem. During the 2(nd) period imipenem usage decreased (slope is -1.28, p=0.002). Prior to the introduction of ertapenem, susceptibility of P. aeruginosa to imipenem increased from 61% to 81% at month 7, but then decreased slightly to 67% at month 9. After the introduction of ertapenem, susceptibility continued to increase; the increasing trend was significant (slope = 1.74, p<0.001). In the 3(rd) period, the median susceptibility (interquartile range) was 88% ( 82% to 95%). This change appeared related to decreased imipenem usage. For every unit decrease in the monthly DDD of imipenem, there was an increase of 0.38% (p=0.008) in the susceptibility of P. aeruginosa to imipenem in the same month. Ertapenem was effective in our antimicrobial stewardship program and may have helped improve the P. aeruginosa antimicrobial susceptibility to imipenem by decreasing unnecessary usage and selective pressure of anti-psueudomonal agents. | | Language | ENG | | Pub Type(s) | JOURNAL ARTICLE
| | PubMed ID | 19786596 |
|
