Is cefoxitin effective against Escherichia coli (E. coli) infections?

Cefoxitin is Effective Against E. coli Infections

Yes, cefoxitin is effective against Escherichia coli infections and is FDA-approved for treating various E. coli infections including urinary tract infections, intra-abdominal infections, and septicemia. 1

Mechanism and Spectrum of Activity

Cefoxitin is a cephamycin antibiotic with the following characteristics:

• Acts by inhibiting bacterial cell wall synthesis
• Has stability against beta-lactamases (both penicillinases and cephalosporinases) produced by many gram-negative bacteria
• Specifically indicated for treating infections caused by E. coli according to FDA labeling 1
• Demonstrates bactericidal activity against E. coli in both laboratory and clinical settings

Clinical Applications for E. coli Infections

Cefoxitin is FDA-approved for treating the following E. coli infections:

• Urinary tract infections
• Intra-abdominal infections including peritonitis and abscesses
• Septicemia
• Skin and skin structure infections
• Gynecological infections
• Lower respiratory tract infections 1

Supporting Evidence for E. coli Coverage

The Surgical Infection Society and Infectious Diseases Society of America (IDSA) guidelines recommend cefoxitin as a single-agent empiric therapy option for mild to moderately severe intra-abdominal infections, which commonly involve E. coli 2.

Recent research supports cefoxitin's effectiveness against E. coli:

• A 2015 study demonstrated that cefoxitin could be considered as a carbapenem-sparing antibiotic for some ESBL-E infections, particularly those related to E. coli 3
• A 2012 murine model study showed cefoxitin was as effective as carbapenems in treating urinary tract infections caused by E. coli harboring CTX-M-15-type extended-spectrum β-lactamase 4

Considerations and Limitations

While cefoxitin is effective against E. coli, there are some important considerations:

• For severe infections, particularly those with suspected ESBL-producing E. coli, carbapenems may be preferred 2
• The WHO Expert Committee noted that cefoxitin was considered redundant because ceftriaxone offers broader gram-negative coverage 2
• Cefoxitin has limited activity against Pseudomonas and Enterobacter species 5

Clinical Decision Making

When considering cefoxitin for E. coli infections:

1. For mild-moderate infections: Cefoxitin is an appropriate choice for uncomplicated E. coli infections
2. For severe infections: Consider carbapenems or newer agents depending on local resistance patterns
3. For ESBL-producing E. coli: While some evidence supports cefoxitin use 3, 4, carbapenems remain first-line therapy for severe infections
4. For mixed aerobic-anaerobic infections: Cefoxitin's coverage of both E. coli and anaerobes makes it particularly useful 5

Dosing Considerations

For E. coli infections in adults with normal renal function, typical dosing is 1-2 g IV every 6-8 hours, with adjustments needed for renal impairment 1.

In conclusion, cefoxitin remains an effective antibiotic against E. coli infections and can be particularly valuable as a carbapenem-sparing option in appropriate clinical scenarios.