On the Edge of Susceptibility: Cefepime Use in Patients with Carbapenem-Resistant Pseudomonas Aeruginosa Infections

Document Type

Conference Proceeding

Publication Date

3-6-2026

Publication Title

Am J Health Syst Pharm

Keywords

cefepime, adult, antimicrobial therapy, carbapenem resistant Pseudomonas aeruginosa, clinical effectiveness, clinical outcome, clinical practice guideline, conference abstract, controlled study, critically ill patient, drug resistance, drug therapy, drug utilization review, electronic health record, female, human, kidney function, major clinical study, minimum inhibitory concentration, multidrug resistance, nonhuman, pharmacodynamics, pharmacokinetics, pharmacology, phenotype, practice guideline, probability, Pseudomonas infection, retrospective study, sputum culture, therapy

Abstract

Purpose: Carbapenem-resistant Pseudomonas aeruginosa (CRPA) infections are associated with substantial morbidity and mortality, with limited therapeutic options. Although cefepime remains a potential treatment, clinical outcomes may vary even when isolates meet conventional susceptibility breakpoints. Optimizing cefepime dosing is critical to achieve pharmacokinetic/pharmacodynamic (PK/PD) targets, maximize clinical effectiveness, and limit resistance emergence. The purpose of this study is to evaluate cefepime utilization in critically ill patients with CRPA, focusing on minimum inhibitory concentration (MIC) distribution, dosing appropriateness adjusted for renal function, and the probability of achieving established PK/PD targets. Methods: This retrospective medication utilization review will include 150 adults aged ≥18 years admitted to an intensive care or stepdown unit at Henry Ford St. John, Warren, or Madison Heights Hospital between January 1, 2022, and July 31, 2025, with CRPA isolated from blood or sputum cultures who received ≥24 hours of cefepime. Only the first qualifying admission per patient will be analyzed. The primary objective is to determine the proportion of patients receiving cefepime regimens achieving optimal pharmacokinetic/ pharmacodynamic (PK/PD) targets. Secondary objectives include describing resistance phenotypes, characterizing susceptibility to alternative antipseudomonal agents, and assessing temporal MIC trends. Data will be collected from the electronic health record, including patient demographics, renal function, antimicrobial therapy, and microbiology results. Susceptibilities to antipseudomonal agents will be collected to provide comparative resistance profiles. Cefepime dosing will be evaluated against institutional renal dosing guidelines, with optimal regimens defined as probability of target attainment (PTA >90%) based on published PK/PD models, stratified by MIC (< 2, 4, 8, ≥16 µg/mL) and renal function. Isolates will be classified as multidrug-resistant, extensively drug-resistant, or difficult-to-treat. Biannual MIC trends from 2022–2025 will be analyzed. Descriptive statistics will summarize patient characteristics, cefepime utilization patterns, MIC distributions, dosing appropriateness, resistance phenotypes, and temporal trends.

Volume

83

Issue

Supplement_2

First Page

S809

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