Cefepime Administration in Patients with Penicillin Allergy
Introduction to Cefepime Cross-Reactivity
- The American Academy of Allergy, Asthma, and Immunology recommends that cefepime can be safely ordered in patients with a history of severe penicillin allergy, as it has negligible cross-reactivity (approximately 2% risk) due to its dissimilar R1 side chain structure 1, 2
- The risk of cross-reactivity to low-similarity-score cephalosporins (which includes cefepime) in patients with proven penicillin allergy is only 2.11% (95% CI: 0.98-4.46%) 1, 2
- Cross-reactivity is primarily determined by R1 side chain similarity, not the shared beta-lactam ring 1, 2
Clinical Decision Algorithm
- Cefepime can be administered safely due to dissimilar side chains in patients with immediate-type penicillin reactions (anaphylaxis, angioedema, urticaria within 1-6 hours) 1, 2
- Consider administering the first dose in a monitored setting if institutional protocols require it for severe allergy histories 3
- Cefepime can be used without restriction in patients with delayed-type penicillin reactions (rash after >1 hour) 1, 2
- No special monitoring is required for patients with delayed-type penicillin reactions 3
Contraindications for Cefepime Use
- History of severe delayed immunologic reactions (Stevens-Johnson syndrome, toxic epidermal necrolysis, DRESS syndrome) is a contraindication for cefepime use 1, 2
- History of organ-specific reactions (hemolytic anemia, drug-induced liver injury, acute interstitial nephritis) is a contraindication for cefepime use 1, 2
- In these cases, all beta-lactam antibiotics should be avoided 3