title: Cross-reactivity and Tolerability of Ertapenem in Patients With IgE-Mediated Hypersensitivity to β-Lactams.
abstract: OBJECTIVE
  Administration of carbapenems to β-lactam-allergic patients has always been considered potentially harmful because of a 47.4% rate of cross-reactivity to imipenem reported in a single study. Nevertheless, recent studies have shown that the rate of cross-reactivity of imipenem and meropenem with penicillins is lower than 1%. The aim of this study was to evaluate the possibility of using ertapenem in patients with an established IgE-mediated β-lactam allergy.
  
  
  METHODS
  We studied all participants who came to our allergy unit and had a clinical history of immediate hypersensitivity reactions to β-lactams. The inclusion criteria were a positive skin test result to at least 1 β-lactam molecule and/or positive specific IgE (when available). All participants underwent immediate-type skin tests with several β-lactam molecules including ertapenem. Challenges with intravenous ertapenem were performed on 2 different days in patients with negative skin test results.
  
  
  RESULTS
  We examined 49 patients with a clinical history of immediate reactions to β-lactams. All the patients had positive skin tests and/or positive specific IgE to at least 1 β-lactam reagent and negative carbapenem skin tests. Thirty-six patients agreed to undergo the challenges and 35 tolerated the full dose of ertapenem.
  
  
  CONCLUSIONS
  The practice of avoiding carbapenems in patients with β-lactam allergy should be abandoned considering the very low rate of cross-reactivity. β-Lactam-allergic patients who need ertapenem therapy should undergo skin tests and, if negative, a graded challenge to assess tolerability.
authors.affiliation: Department of Allergy, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Buonomo
authors.affiliation: Department of Allergy, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Pascolini
authors.affiliation: Department of Allergy, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Rizzi
authors.affiliation: Department of Allergy, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Aruanno
authors.affiliation: Department of Allergy, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Pecora
authors.affiliation: Department of Allergy, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: A G
authors.initials: AG
authors.lastname: Ricci
authors.affiliation: Department of Allergy, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Mezzacappa
authors.affiliation: Department of Allergy, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Di Rienzo
authors.affiliation: Department of Allergy, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Centrone
authors.affiliation: Department of Allergy, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Nucera
authors.affiliation: Department of Allergy, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Schiavino
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000009:adverse effects*; D003429:Cross Reactions; D004342:Drug Hypersensitivity / Q000097:blood / Q000175:diagnosis* / Q000209:etiology / Q000276:immunology; D000077727:Ertapenem; D005260:Female; D006801:Humans; D015378:Imipenem / Q000009:adverse effects*; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D000077731:Meropenem; D008875:Middle Aged; D012882:Skin Tests; D013845:Thienamycins / Q000009:adverse effects*; D047090:beta-Lactams / Q000009:adverse effects*
chemical_list: D000900:Anti-Bacterial Agents; D013845:Thienamycins; D047090:beta-Lactams; D007073:Immunoglobulin E; D015378:Imipenem; D000077731:Meropenem; D000077727:Ertapenem
keywords: Cross-reactivity; Ertapenem; IgE-mediated hypersensitivity; β-lactams