Is cefepime a penicillin?

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From the Guidelines

No, cefepime is not a penicillin. Cefepime is a fourth-generation cephalosporin antibiotic, while penicillins are a different class of beta-lactam antibiotics. Although both cephalosporins and penicillins belong to the broader beta-lactam family and work by inhibiting bacterial cell wall synthesis, they have different chemical structures and antimicrobial spectrums.

Key Points

  • Cefepime has broader coverage against gram-negative bacteria, including Pseudomonas aeruginosa, and maintains good activity against gram-positive organisms.
  • Patients with penicillin allergies may sometimes have cross-reactivity with cephalosporins, though this is less common with later-generation cephalosporins like cefepime.
  • The risk of cross-reactivity is approximately 1-3% for patients with confirmed penicillin allergies, as reported in a recent study 1.
  • Cefepime is typically administered intravenously for serious infections such as pneumonia, urinary tract infections, and febrile neutropenia.

Considerations

  • A study published in the Journal of Allergy and Clinical Immunology in 2022 1 provides evidence that cross-reactivity between penicillins and cephalosporins is negligible, even in patients with confirmed penicillin allergies.
  • The same study suggests that the risk of cross-reactivity may be higher among drugs with similar side chains, but cefepime has a unique side chain that reduces the risk of cross-reactivity.
  • It is essential to note that while skin testing is not recommended for cephalosporins, it may be advisable for specific patients with multiple drug allergies due to the possibility of coexisting sensitivities, as mentioned in a study 1.

Administration and Usage

  • Cefepime is usually administered intravenously, and the recommended dosage varies depending on the type and severity of the infection.
  • The drug has been shown to be effective in treating a range of infections, including pneumonia, urinary tract infections, and febrile neutropenia, with a low risk of cross-reactivity in patients with penicillin allergies, as supported by recent evidence 1.

From the FDA Drug Label

CONTRAINDICATIONS Cefepime for injection is contraindicated in patients who have shown immediate hypersensitivity reactions to cefepime or the cephalosporin class of antibiotics, penicillins or other beta-lactam antibiotics.

  • Cefepime is a cephalosporin, which is a separate class of beta-lactam antibiotics from penicillins.
  • The drug label does not state that cefepime is a penicillin, but rather lists it as a separate class.
  • Therefore, cefepime is not a penicillin 2

From the Research

Classification of Cefepime

  • Cefepime is classified as a fourth-generation cephalosporin 3, 4, 5, 6, 7
  • It is not a penicillin, but rather a distinct class of beta-lactam antibiotics 3, 4, 5, 6, 7

Comparison with Other Antibiotics

  • Cefepime has a broader spectrum of antibacterial activity than third-generation cephalosporins 4, 5, 7
  • It is stable against many common plasmid- and chromosomally-mediated beta-lactamases 4, 5, 7
  • Cefepime is as effective as ceftazidime, cefotaxime, and other antibiotics in treating various infections 4, 5, 7

Mechanism of Action

  • Cefepime exerts its antimicrobial effect by attaching to specific penicillin-binding proteins, disrupting cell-wall synthesis 7
  • Its zwitterionic structure and side chain contribute to its stability against beta-lactamases 3, 7

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Cefepime.

Pharmacotherapy, 1994

Research

Cefepime: a review of its use in the management of hospitalized patients with pneumonia.

American journal of respiratory medicine : drugs, devices, and other interventions, 2003

Research

Cefepime and its role in pediatric infections.

Recent patents on anti-infective drug discovery, 2008

Research

Cefepime: a new fourth-generation cephalosporin.

American journal of hospital pharmacy, 1994

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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