title: Tolerability of aztreonam and carbapenems in patients with IgE-mediated hypersensitivity to penicillins.
abstract: BACKGROUND
  Studies performed on samples larger than 100 subjects with a documented IgE-mediated hypersensitivity to penicillins have demonstrated a cross-reactivity rate of approximately 1% between penicillins and both imipenem and meropenem, whereas a single study found a cross-reactivity rate of 6.2% with aztreonam in 16 such subjects.
  
  
  OBJECTIVE
  To assess the cross-reactivity and tolerability of aztreonam and 3 carbapenems (imipenem-cilastatin, meropenem, and ertapenem) in patients with documented IgE-mediated hypersensitivity to penicillins.
  
  
  METHODS
  A total of 212 consecutive subjects with immediate reactions to penicillins and positive results on skin tests to at least 1 penicillin reagent underwent skin tests with aztreonam and carbapenems; subjects with negative results were challenged with escalating doses of aztreonam and carbapenems.
  
  
  RESULTS
  All subjects displayed negative skin test results to both aztreonam and carbapenems; 211 accepted challenges and tolerated them. Challenges were not followed by full therapeutic courses.
  
  
  CONCLUSIONS
  These data indicate the tolerability of both aztreonam and carbapenems in penicillin-allergic subjects. In those who especially require these alternative β-lactams, however, we recommend pretreatment skin tests, both because rare cases of cross-reactivity have been reported and because negative results indicate tolerability.
authors.affiliation: Allergy Unit, Complesso Integrato Columbus, Rome, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Gaeta
authors.affiliation: Allergy Unit, Complesso Integrato Columbus, Rome, Italy.
authors.forename: Rocco Luigi
authors.initials: RL
authors.lastname: Valluzzi
authors.affiliation: Allergy Unit, Complesso Integrato Columbus, Rome, Italy.
authors.forename: Cristiana
authors.initials: C
authors.lastname: Alonzi
authors.affiliation: Allergy Unit, Complesso Integrato Columbus, Rome, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Maggioletti
authors.affiliation: Allergy Unit, Complesso Integrato Columbus, Rome, Italy.
authors.forename: Cristiano
authors.initials: C
authors.lastname: Caruso
authors.affiliation: Allergy Unit, Complesso Integrato Columbus, Rome, Italy; IRCCS Oasi Maria S.S., Troina, Italy. Electronic address: antoninoromano@h-columbus.it.
authors.forename: Antonino
authors.initials: A
authors.lastname: Romano
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001398:Aztreonam / Q000009:adverse effects* / Q000737:chemistry; D015780:Carbapenems / Q000009:adverse effects* / Q000737:chemistry; D003429:Cross Reactions; D004342:Drug Hypersensitivity / Q000453:epidemiology / Q000276:immunology*; D057915:Drug Substitution; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000453:epidemiology / Q000276:immunology*; D007108:Immune Tolerance; D008297:Male; D008875:Middle Aged; D010406:Penicillins / Q000009:adverse effects* / Q000737:chemistry; D012882:Skin Tests; D055815:Young Adult
chemical_list: D015780:Carbapenems; D010406:Penicillins; D001398:Aztreonam
keywords: Aztreonam; cross-reactivity; ertapenem; imipenem; meropenem; penicillin allergy; skin tests; tolerability