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sulfa allergy

Epidemiology: - about 3% of patients develop allergic reactions to sulfonamides (sulfonylarylamines, the sulfa antibiotics) [4] Clinical manifestations: - hypersensitivity* a) most reactions are mild, i.e. urticaria b) anaphylaxis c) Stevens-Johnson syndrome * PEN-FAST (SULF-FAST) criteria for predicting sulfonamide hypersensitivity [6] - allergic event occurred anaphylaxis/angioedema or severe cutaneous adverse reaction (2 points) - treatment was required for allergic event (1 point) * a PEN-FAST (SULF-FAST) of <3 associated with <5% risk of hypersensitivity reaction - a score >= 3 associated with >20% risk of hypersensitivity reaction [6] Management: 1) Cross reactivity of non antibiotic sulfa drugs is rare, thus use of non-antibiotic sulfonamides is not contraindicated* [4,7] a) zonisamide (Zonegran) -> contraindicated b) sulfasalazine (Azulfidine) -> avoid c) thiazide diuretics are not contraindicated - hydrochlorothiazide - chlorthalidone - indapamide (Lozol) d) loop diuretics are not contraindicated e) celecoxib is not contraindicated f) use with caution in patients with severe sulfa reactions g) amprenavir (Agenerase) is a sulfonamide (use with caution) h) carbonic anhydrase inhibitors (insufficient data) i) COX-2 inhibitors celecoxib (Celebrex) & valdecoxib (Bextra) [3] - insufficient data - still contraindicated j) sulfonylureas - cross-reactivity of sulfonamide antibiotics & sulfonylureas is rare [5] - no reports of cross-sensitivity with glipizide (Glucotrol) - rare reports of cross-reaction with glyburide (Diabeta, Micronase) & tolbutamide (Orinase) k) sumatriptan, sotalol, topiramate ? [4] l) saccharin 2) drugs that contain sulfur, but are NOT sufonamides are okay for patients allergic to sulfonamides: a) captopril b) omeprazole c) amoxicillin c) sulfites d) sulfates * Sulfonamide antibiotic reactions probably confer increased risk for drug reaction with non-antibiotic sulfonamides as a result of increased susceptibility to drug reactions rather than cross-reactivity of sulfonamides [2]

Related

sulfonamide

General

type B drug reaction; drug-induced hypersensitivity syndrome; drug rash with eosinophilia & systemic symptoms (DIHS, DRESS)

References

  1. Prescriber's Letter 7(7):37 2000
  2. Strom BL et al, N Engl J Med 349:1628, 2003 PMID: 14573734
  3. Prescriber's Letter 11(7):42 2004 Detail-Document#: 200702 (subscription needed) http://www.prescribersletter.com
  4. Prescriber's Letter 11(7):42 2004 Sulfa Drugs and the Sulfa-allergic Patient Detail-Document#: 211113 (subscription needed) http://www.prescribersletter.com
  5. NEJM Knowledge+ Endocrinology
  6. Waldron JL et al. Development and validation of a sulfa antibiotic allergy clinical decision rule. JAMA Netw Open 2023 Jun 5; 6:e2316776. PMID: 37273210 PMCID: PMC10242418 Free PMC article https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2805577
  7. NEJM Knowledge+ Allergy/Immunology - Dorn JM, Alpern M, McNulty C, Volcheck GW. Sulfonamide Drug Allergy. Curr Allergy Asthma Rep. 2018 Jun 6;18(7):38. PMID: 29876667 Review. - Khan DA, Knowles SR, Shear NH. Sulfonamide Hypersensitivity: Fact and Fiction. J Allergy Clin Immunol Pract. 2019 Sep-Oct;7(7):2116-2123. PMID: 31495421 Review.