Objective:

To review the literature evaluating the cross-hypersensitivity between carbapenem and penicillin antibiotics.

Data Sources:

Primary literature was accessed through MEDLINE (1980–June 2004), EMBASE (1980–December 2004), International Pharmaceutical Abstracts, PubMed, and references of reviewed articles. Key search terms were carbapenem, imipenem, meropenem, ertapenem, drug hypersensitivity, and penicillin allergy.

Study Selection and Data Extraction:

All articles describing clinical studies involving the use of carbapenem antibiotics in patients allergic to penicillin were reviewed.

Data Synthesis:

Four studies assessed carbapenem hypersensitivity in penicillin-allergic patients. Original estimates deemed the cross-reactivity to be 50% based on skin testing in a small number of patients; however, 3 more recent retrospective analyses indicate the overall incidence to be approximately 10%. The retrospective nature and presence of confounding factors in the more recent studies make it difficult to apply the lower estimates of carbapenem cross-sensitivity to a general patient population. The majority of cross-reactivity reactions reported was the development of a rash or hives.

Conclusions:

With minimal data available, the incidence of allergic reaction to carbapenem antibiotics in patients with self-reported penicillin allergy is likely less than the original skin test–determined estimates of 50%. However, caution should be used in patients with previously reported anaphylactic reactions to penicillin. A detailed allergy history is important in determining the clinical consequences of the potential cross-reactivity of carbapenem antibiotics in penicillin-allergic patients.