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.

Prophylactic Effect of Erythropoietin Injection to Prevent Acute Mountain Sickness: An Open-Label Randomized Controlled Trial

“…However, several experts are concerned about the side effects of this drug, namely allergic reactions such as blood dyscrasias, Stevens-Johnson syndrome, renal failure, and toxic epidermal necrolysis (21, 22). In the present study, all participants were given sildenafil during their stay at Deurali and ABC.…”

Safety of carbonic anhydrase inhibitors

“…This applies even to the topical inhibitors, because although systemic absorption is insufficient to cause CA inhibition elsewhere, the even very small degree of absorption may present enough antigen to elicit a full allergic/ anaphylactic response. If the reaction to a past sulfonamide, particularly not of a CA-inhibiting subclass, was minor, for example, itching, rhinitis, then it is unlikely that a serious cross-reaction would occur [118,120,121]. However, whether or not a CA inhibitor should be used, the real small risk ought to be discussed with the patient with respect to the benefits or critical need.…”

Sulfa Allergy and Therapeutic Decisions

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