Cefepime Breakpoint for E. coli UTI in Males
The cefepime susceptibility breakpoint for Escherichia coli causing urinary tract infections is ≤8 μg/mL for susceptible, with this standard applying regardless of patient sex. 1
Current CLSI Breakpoint Standards
The susceptible breakpoint for cefepime against E. coli is ≤8 μg/mL, which has remained unchanged despite revisions to other cephalosporin breakpoints in 2010-2011 1
The intermediate category is not clearly defined in current CLSI guidelines for cefepime, with resistant typically defined as MIC >8 μg/mL 1
These breakpoints apply to all Enterobacteriaceae including E. coli, regardless of infection site or patient demographics 1
Clinical Application for UTI Treatment
For urinary tract infections specifically, cefepime achieves high urinary concentrations that may allow successful treatment even at higher MICs within the susceptible range 2
In a clinical trial of hospitalized patients with complicated UTI, cefepime 500 mg every 12 hours achieved 89% satisfactory clinical response and 85% pathogen eradication for E. coli infections 2
The standard dosing for UTI treatment is typically 1-2 grams every 8-12 hours IV, which achieves urinary concentrations far exceeding the MIC breakpoint 2
Important Caveats for ESBL-Producing Strains
The ≤8 μg/mL breakpoint has significant limitations for ESBL-producing E. coli, which may test as "susceptible" but have uncertain clinical efficacy 1
Many ESBL-producing E. coli and Klebsiella isolates remain technically susceptible by the ≤8 μg/mL breakpoint, but clinical outcomes with cefepime for these infections remain unclear 1
For definitive therapy of ESBL-producing E. coli, cefepime should only be used when the MIC is ≤2 μg/mL (CLSI) or ≤1 μg/mL (EUCAST), with higher doses potentially considered for MICs of 4-8 μg/mL 3
ESBL testing may still be valuable for infection control purposes even though routine reporting changes are no longer required 1
Sex-Specific Considerations
There is no sex-specific breakpoint modification for cefepime against E. coli - the ≤8 μg/mL standard applies equally to male and female patients 1
The question of male versus female UTI is clinically relevant for treatment duration and complexity classification, but does not alter the microbiological susceptibility breakpoint 1