title: Sulfonamide cross-reactivity: fact or fiction?
abstract: OBJECTIVE
  To provide a critical and comprehensive review of the literature, specifically case reports and observational studies used to support the concept of cross-reactivity between sulfonylarylamines and non-sulfonylarylamines.
  
  
  METHODS
  A list of medications was formulated from several different review articles. A MEDLINE/PubMed search was conducted (1966-March 2004) using the individual medications and the MeSH terms of drug hypersensitivity/etiology, sulfonamides/adverse effects, and/or cross-reaction.
  
  
  METHODS
  A critical review of the methodology and conclusions for each article found in the search was conducted. The manufacturer's package insert (MPI) for each drug was examined for a statement concerning possible cross-reactivity in patients with a sulfonamide allergy. If indicated, the manufacturers were contacted to obtain any clinical data supporting the statement.
  
  
  RESULTS
  A total of 33 medications were identified. Seventeen (51.5%) of the MPIs contained statements of varying degrees concerning use in patients with a "sulfonamide" allergy; 21 case series, case reports, and other articles were found.
  
  
  CONCLUSIONS
  After a thorough critique of the literature, it appears that the dogma of sulfonylarylamine cross-reactivity with non-sulfonylarylamines is not supported by the data. While many of the case reports on the surface support the concept of cross-reactivity, on closer examination the level of evidence in many of the cases does not conclusively support either a connection or an association between the observed cause and effect.
authors.affiliation: Adult Internal Medicine Pharmacy Resident, Department of Pharmacy Services, Virginia Commonwealth University Medical Center-Medical College of Virginia (MCV) Campus, Richmond, VA 23298-0042, USA.
authors.forename: Kelly K
authors.initials: KK
authors.lastname: Johnson
authors.forename: David L
authors.initials: DL
authors.lastname: Green
authors.forename: Jason P
authors.initials: JP
authors.lastname: Rife
authors.forename: Lynn
authors.initials: L
authors.lastname: Limon
mesh_terms: D016861:Cyclooxygenase Inhibitors / Q000009:adverse effects / Q000737:chemistry; D004232:Diuretics / Q000009:adverse effects / Q000737:chemistry; D004342:Drug Hypersensitivity / Q000209:etiology; D004347:Drug Interactions; D004348:Drug Labeling; D006801:Humans; D013449:Sulfonamides / Q000009:adverse effects / Q000737:chemistry*
chemical_list: D016861:Cyclooxygenase Inhibitors; D004232:Diuretics; D013449:Sulfonamides