title: Approach to managing patients with sulfa allergy: use of antibiotic and nonantibiotic sulfonamides.
abstract: OBJECTIVE
  To present an approach to use of sulfonamide-based (sulfa) medications for patients with sulfa allergy and to explore whether sulfa medications are contraindicated for patients who require them but are allergic to them.
  
  
  METHODS
  A search of current pharmacology textbooks and of MEDLINE from 1966 to the present using the MeSH key words "sulfonamide" and "drug sensitivity" revealed review articles, case reports, one observational study (level II evidence), and reports of consensus opinion (level III evidence).
  
  
  RESULTS
  Cross-reactivity between sulfa antibiotics and nonantibiotics is rare, but on occasion it can affect the pharmacologic and clinical management of patients with sulfa allergy.
  
  
  CONCLUSIONS
  How a physician approaches using sulfa medications for patients with sulfa allergy depends on the certainty and severity of the initial allergy, on whether alternatives are available, and on whether the contemplated agent belongs to the same category of sulfa medications (ie, antibiotic or nonantibiotic) as the initial offending agent.
authors.affiliation: Civic Campus site, Department of Family Medicine, University of Ottawa, Ontario, Canada. dponka@ottawahospital.on.ca
authors.forename: David
authors.initials: D
authors.lastname: Ponka
mesh_terms: D000900:Anti-Bacterial Agents / Q000009:adverse effects / Q000737:chemistry / Q000276:immunology; D003429:Cross Reactions; D004232:Diuretics / Q000009:adverse effects / Q000737:chemistry / Q000276:immunology; D004342:Drug Hypersensitivity / Q000209:etiology* / Q000517:prevention & control; D006801:Humans; D013449:Sulfonamides / Q000009:adverse effects* / Q000737:chemistry / Q000276:immunology
chemical_list: D000900:Anti-Bacterial Agents; D004232:Diuretics; D013449:Sulfonamides