1036. The Impact of Ertapenem Use on Resistance Trends within an Eleven Hospital System
Session: Poster Abstract Session: Stewardship: Improving Treatments
Friday, October 4, 2013
Room: The Moscone Center: Poster Hall C
Background: Ertapenem’s greatest appeal is its once daily dose and broad spectrum activity, including coverage of ESBL and AmpC producers. Since 2001, ertapenem’s use has become widespread based on these benefits. However, this use may be contributing to the recent increasing resistance rates with Carbapenem Resistant Enterobacteriaceae (CRE). Credito et al. examined minimum inhibitory concentrations (MIC) with P. aeruginosa, E. Coli, K. pneumoniae and A. baumannii organisms and found 86% of ertapenem resistant organisms were K. pneumoniae. These strains had higher MICs to meropenem and ertapenem compared to doripenem and imipenem.

Methods: Inpatient and outpatient ertapenem and anti-pseudomonal carbapenems use was collected from the medical electronic system. The annual inpatient use data for each hospital was normalized for each drug by defined daily doses per 1,000 patient days. Resistance rates were collected from the antibiograms of the eleven Franciscan Alliance Hospitals to determine the trends in annual resistance rates to imipenem and ertapenem, as well as other carbapenems, if stated. The number of CREs were collected over the same timeframe.

Results: In five of eleven hospitals, ertapenem use correlated with decreasing P. aeruginosas susceptibility rates to imipenem over a three year period. In addition, three hospitals had a correlation with ertapenem use and the reported rate of CREs.

 

Hospital

 

2009

2010

2011

A

CRE Rate (%)

0

0

0

PSA Susc (%)

-

91

97

Ert Use*

1.9

1.1

0.2

B

CRE Rate (%)

1

7

9

PSA Susc (%)

80

83

85

Ert Use*

14.2

17.2

13.2

C

CRE Rate (%)

0

0

1

PSA Susc (%)

91

85

86

Ert Use*

4.0

11.2

2.5

D

CRE Rate (%)

0

0

1

PSA Susc (%)

91

85

86

Ert Use*

3.9

6.8

3.7

E

CRE Rate (%)

1

0

1

PSA Susc (%)

86

100

96

Ert Use*

-

1.0

1.9

F

CRE Rate (%)

1.1

22.5

13.6

PSA Susc (%)

62

56

62

 

Ert Use*

15.3

44.7

24.5

*Defined as defined daily doses/1,000 patient days

Conclusion: The inpatient use of ertapenem has demonstrated a correlation to five hospital’s CRE rates and three hospital’s P. aeruginosa susceptibility. Although this is only a snapshot of the impact of ertapenem CRE rates and P. aeruginosa resistance, this data may suggest that the use of ertapenem is a potential contributing factor to the decreased P. aeruginosa susceptibilities to imipenem and hospital CRE rates.

Caitlin Handler, PharmD, Andrea Stock, PharmD and S. Christian Cheatham, PharmD, Pharmacy, Franciscan St. Francis Health, Indianapolis, IN

Disclosures:

C. Handler, None

A. Stock, None

S. C. Cheatham, None

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