What is the effectiveness of Cefepime (Cefepime) against Escherichia coli (E. coli)?

From the Guidelines

Cefepime is not the preferred antibiotic choice for E. coli infections due to the increasing prevalence of extended-spectrum beta-lactamase (ESBL) producing strains, and carbapenems like meropenem are generally recommended for empiric coverage. For most E. coli infections, the choice of antibiotic should be guided by susceptibility testing and local resistance epidemiology. However, in the absence of susceptibility testing, carbapenems are generally preferred due to their broad spectrum of activity and stability against many beta-lactamases. Cefepime, a fourth-generation cephalosporin, may still be effective against some E. coli strains, but its use should be guided by susceptibility testing and careful consideration of the potential for resistance 1. The dosage and treatment duration of cefepime or alternative antibiotics should be determined based on the severity and site of infection, as well as the patient's renal function and other comorbidities.

Some key points to consider when choosing an antibiotic for E. coli infections include:

• The increasing prevalence of ESBL-producing E. coli strains, which may be resistant to cefepime and other beta-lactam antibiotics 1
• The importance of susceptibility testing to guide antibiotic choice and ensure effective treatment 1
• The potential for carbapenem resistance, which may limit the effectiveness of these antibiotics in some cases 1
• The need for careful consideration of the patient's renal function and other comorbidities when choosing an antibiotic and determining the dosage and treatment duration 1

In general, the choice of antibiotic for E. coli infections should be guided by a careful consideration of the potential benefits and risks, as well as the latest evidence and guidelines. Carbapenems like meropenem are generally recommended for empiric coverage of suspected ESBL producers, but cefepime may still be effective against some E. coli strains, and susceptibility testing should be used to guide antibiotic choice.

From the FDA Drug Label

Cefepime has been shown to be active against most isolates of the following microorganisms, both in vitro and in clinical infections as described in the INDICATIONS AND USAGE section. Gram-negative bacteria Enterobacter spp Escherichia coli Klebsiella pneumoniae Proteus mirabilis Pseudomonas aeruginosa

Cefepime is effective against E. coli.

• The drug label indicates that cefepime is active against most isolates of E. coli, both in vitro and in clinical infections.
• The susceptibility test interpretive criteria for cefepime are provided in Table 4, which includes the minimum inhibitory concentrations (MICs) and disk diffusion zone diameters for E. coli.
• According to the table, E. coli is considered susceptible to cefepime if the MIC is ≤2 mcg/mL or the disk diffusion zone diameter is ≥25 mm 2.

From the Research

Cefepime versus E. coli

• Cefepime has been shown to be effective against E. coli in several studies 3, 4, 5.
• In a study published in 2003, cefepime was found to have good activity against Gram-negative organisms, including E. coli 3.
• A study published in 1993 found that cefepime 1 g bd was effective in treating urinary tract infections caused by E. coli, with a clinical cure rate of 94% and pathogen eradication rate of 93% 4.
• Another study published in 1996 compared the efficacy and safety of cefepime and ceftazidime in treating urinary tract infections, including those caused by E. coli, and found that cefepime produced a satisfactory clinical response in 89% of patients and eradicated 85% of pathogens 5.
• More recently, a study published in 2025 found that cefepime-enmetazobactam, a combination of cefepime and a beta-lactamase inhibitor, has potent activity against ESBL-producing Enterobacterales, including E. coli 6.

Mechanism of Action

• Cefepime is a fourth-generation cephalosporin with a broad spectrum of bactericidal activity and enhanced stability to degradation by chromosomal and plasmid-mediated AmpC cephalosporinases as well as carbapenemase OXA-48 like enzymes 6.
• Cefepime-enmetazobactam is a beta-lactam/beta-lactamase inhibitor combination that restores cefepime activity in vitro and in vivo against ESBL-producing Enterobacterales 6.

Clinical Implications

• Cefepime and cefepime-enmetazobactam may be effective treatment options for infections caused by E. coli, including those that are resistant to other antibiotics 3, 4, 5, 6.
• The use of cefepime-enmetazobactam may help to reduce the reliance on carbapenems and other broad-spectrum antibiotics, which is important for mitigating the development of antibiotic resistance 6.