To the Editor.
—Recently, a discussion arose among the physicians in our ophthalmology residency program regarding the use of acetazolamide (Diamox, Lederle Laboratories Pearl River, NY) in patients who report a "sulfa" allergy or hypersensitivity. Acetazolamide is a sulfonamide drug related to many other drugs of this class, including sulfamethoxazole, thiazide diuretics, and certain oral hypoglycemics. Although the majority of the staff ophthalmologists felt that "sulfa" allergy was a relative contraindication, a significant minority felt the use of acetazolamide in such a patient was absolutely contraindicated.A search of the MEDLINE and TOXLINE data bases (1966 through 1989) revealed more than 2000 references to acetazolamide, but not a single report of cross-sensitivity. In addition, the manufacturer of Diamox (Lederle Laboratories) has only a few reports on file of sulfonamide-type hypersensitivity reactions to Diamox. None of these reactions occurred in a patient with a well-documented history of "sulfa" allergy (written communication
Stock JG. Sulfonamide Hypersensitivity and Acetazolamide. Arch Ophthalmol. 1990;108(5):634-635. doi:10.1001/archopht.1990.01070070020005