Patients Allergic to Penicillin or Cephalosporins: Risks of Prescribing Carbapenems Little is known about the true cross-reactivity between the £-lactam-containing carbapenems (meropenem, imipenem, and ertapenem) and the penicillins and cephalosporins. However, the limited evidence available indicates that the risk of cross-allergy is higher between penicillins and carbapenems than between penicillins and cephalosporins. In one study, [...]

Cephalosporin-Allergic Patients Risks of Prescribing Cephalosporins Patients experiencing an allergic reaction to a particular cephalosporin should not receive that cephalosporin again. The risk of cross-reaction when a different cephalosporin is given is not known precisely, but it may be influenced by the various side chains possibly involved in the immune response. One study showed that [...]

Risks of Prescribing Cephalosporins Skin reactions to cephalosporins (e.g., urticaria, rash, pruritis) occur at a frequency of 1% to 3%. Anaphylaxis is rare (0.0001% to 0.1%). Because cephalosporins also contain the £-lactam ring (Figure 1), there is potential for cross-reactivity in penicillin-allergic patients. Complicating the issue is the fact that hypersensitivity reactions with cephalosporins may [...]

Penicillin Allergy The true incidence of penicillin allergy is unknown, although 5% to 20% of the population report this type of allergy, often with a vague or unconfirmed history. The penicilloyl derivative is the most frequently implicated metabolite in IgE-mediated reactions to penicillin. Anaphylaxis, the most severe of the type I reactions, occurs in 0.01% [...]

Classification of Allergic Reactions Allergic reactions to 6-lactams have been categorized by clinical syndrome, immune mechanism, or time to onset (Table 1). Type 1 reactions are mediated by IgE antibodies directed at specific combinations of metabolites and serum proteins. When the metabolite-protein complex is recognized and cross-links with specific preformed IgE antibodies bound to tissue [...]

Two databases — MEDLINE (from 1994 to 2004 for penicillins and cephalosporins and from 1985 to 2004 for carbapenems) and Reactions (from 1983 to 2003) — were searched for pertinent English- language articles (limited to human studies). The MeSH terms “drug hypersensitivity”, “penicillins”, “cephalosporins”, and “carbapenems” and the key words “allergy”, “imipenem”, “meropenem”, and “ertapenem” [...]

INTRODUCTION B-Lactam antibiotics, which comprise the penicillin, cephalosporin, and carbapenem families, are so called because they all have a £-lactam ring (Figure 1). £-Lactam agents are frequently prescribed because they are bactericidal, relatively inexpensive, effective against a wide range of pathogens, and well tolerated. The most frequent side effect reported with £-lactam antibiotics, particularly penicillin, [...]