Diuretic Renal Scintigraphy in Patients with Sulfonamide Allergies: Possible Alternative Use of Ethacrynic Acid

Furosemide may trigger life-threatening sulfonamide cross-hypersensitivity reactions, posing a dilemma in patients who need diuretic renal scintigraphy. We present our experience using ethacrynic acid as a nonsulfonamide alternative diuretic in 5 patients, with a discussion of the diuretic molecular structure, potential side effects, protocol development, and imaging results. Diuretic renal scintigraphy using ethacrynic acid provided useful information about the obstruction status in all patients, with no adverse clinical impact. Ethacrynic acid is a potential alternative to furosemide for patients with severe sulfonamide reactions.