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Impact of Cefepime Susceptible-Dose-Dependent MIC for Enterobacteriaceae on Reporting and Prescribing

Christina G Rivera1, Prasanna P Narayanan2, Robin Patel3

  • 1Hospital Pharmacy Services, Mayo Clinic, Rochester, Minnesota, USA rivera.christina@mayo.edu.

Antimicrobial Agents and Chemotherapy
|April 13, 2016
PubMed

Insights

The Clinical and Laboratory Standards Institute (CLSI) updated cefepime breakpoints to include a susceptible-dose-dependent (SDD) category for Enterobacteriaceae. However, few SDD isolates were treated with cefepime, with carbapenems being the preferred choice.

Area of Science:

  • Clinical microbiology and infectious diseases
  • Antimicrobial stewardship and resistance

Background:

  • The Clinical and Laboratory Standards Institute (CLSI) revised cefepime breakpoints, introducing a susceptible-dose-dependent (SDD) category for Enterobacteriaceae.
  • This revision aimed to guide the use of higher cefepime doses for specific bacterial isolates.
  • Understanding the clinical application of these new breakpoints is crucial for effective antimicrobial therapy.

Purpose of the Study:

  • To evaluate the clinical utilization of the new CLSI cefepime susceptible-dose-dependent (SDD) breakpoints for Enterobacteriaceae.
  • To determine the proportion of Enterobacteriaceae isolates falling into the SDD category and assess treatment patterns for these isolates.

Main Methods:

  • Retrospective analysis of Enterobacteriaceae isolates.
  • Identification of isolates with cefepime minimum inhibitory concentrations (MICs) falling within the SDD range.
  • Review of antimicrobial prescribing data for patients with SDD isolates.

Main Results:

  • 1.6% of Enterobacteriaceae isolates exhibited cefepime susceptible-dose-dependent (SDD) MICs.
  • Escherichia coli was the most frequently identified organism within the SDD category.
  • Cefepime was prescribed for only 4.8% of SDD isolates; carbapenems were the predominant treatment choice.

Conclusions:

  • Enterobacteriaceae isolates with cefepime SDD MICs are infrequently treated with cefepime at this institution.
  • The current clinical practice deviates from the intended use of higher cefepime doses for SDD isolates.
  • Further investigation into treatment guidelines and clinician awareness regarding the cefepime SDD category is warranted.

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