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Guidelines
Beta-lactams in Patients with Allergy

Beta-lactams in Patients with Allergy

Background

  • Early data done in the 1970’s suggested that cephalosporins induce reactions in patients with PCN allergy at a rate of ~8%, however this data was flawed by a lack of defining “allergy” (many patients had non-IgE mediated rashes) and prior to the 1980’s cephalosporins were contaminated with PCN in the manufacturing process
  • Recent studies report allergic reactions to occur in < 1% of patients on cephalosporins with proven PCN IgE mediated allergy, which is not greater than the background rate of cephalosporin hypersensitivity reactions in non-PCN allergic patients
    • This data has debunked the commonly taught practice of avoiding cephalosporins in patients with PCN allergy
  • For more information visit the ASP IntraNet Page on Arc

Penicillin/Cephalosporin/Carbapenem Guidelines

PCN

  • Perform PCN skin testing or use an alternate antibiotic class

Cephalosporin

  • Give any cephalosporin

Carbapenem

  • Give any carbapenem

PCN

  • For history of non-life-threatening reaction (i.e. rash) could perform a graded challenge

Cephalosporin

  • Give any cephalosporin

Carbapenem

  • Give any carbapenem

PCN

  • Give any penicillin

Cephalosporin

  • Consult “Oral Antibiotics with Similar Side-Chains”
  • If side chains are not shared between the offending and desired cephalosporin, may give that particular cephalosporin

Carbapenem

  • Give any carbapenem

Side-Chains

The cephalosporin 6-membered beta-lactam ring structure undergoes rapid fragmentation and loss of ring structure in vivo, and thus is unlikely responsible for any cross-reactivity

Attention has focused on side-chain structural similarities to predict cross-reactivity between cephalosporins