title: Acetazolamide and sulfonamide allergy: a not so simple story.
abstract: Allergies and adverse reactions to sulfonamide medications are quite common. Two distinct categories of drugs are classified as sulfonamides: antibiotics and nonantibiotics. The two groups differ in their chemical structure, use, and the rate at which adverse reactions occur. Cross-reactivity between the two groups has been implied in the past, but is suspect. Acetazolamide, from the nonantibiotic group, is routinely used in the prevention and treatment of high altitude issues and may not need to be avoided in individuals with a history of sulfonamide allergy. This review addresses the differences between the groups and the propensity for intergroup and intragroup adverse reactions based on the available literature. We also examine the different clinical presentations of allergy and adverse reactions, from simple cutaneous reactions with no sequelae through Stevens-Johnson syndrome and anaphylaxis, with risk for significant morbidity and mortality. We offer a systematic approach to determine whether acetazolamide is a safe option for those with a history of allergy to sulfonamides.
authors.affiliation: Department of Emergency Medicine and Emergency Medicine Residency, Maricopa Medical Center, 2601 East Roosevelt Street, Phoenix, AZ 85008, USA. tkkellyq.com
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Kelly
authors.forename: Peter H
authors.initials: PH
authors.lastname: Hackett
mesh_terms: D000086:Acetazolamide / Q000009:adverse effects* / Q000737:chemistry; D000743:Anemia, Hemolytic / Q000150:complications; D002257:Carbonic Anhydrase Inhibitors / Q000009:adverse effects* / Q000737:chemistry; D003429:Cross Reactions; D004342:Drug Hypersensitivity / Q000209:etiology*; D004347:Drug Interactions; D005955:Glucosephosphate Dehydrogenase Deficiency / Q000150:complications; D006801:Humans; D015394:Molecular Structure; D013262:Stevens-Johnson Syndrome / Q000139:chemically induced / Q000209:etiology; D013449:Sulfonamides / Q000009:adverse effects* / Q000737:chemistry
chemical_list: D002257:Carbonic Anhydrase Inhibitors; D013449:Sulfonamides; D000086:Acetazolamide