Which diuretic is typically contraindicated in patients with a sulfa allergy?

Furosemide is an example of a loop diuretic that is structurally related to sulfonamides. Patients who have a known sulfa allergy may experience an allergic reaction when taking furosemide due to this chemical similarity. Because of this association, healthcare providers exercise caution and often consider alternatives for managing fluid retention or hypertension in these patients.

Thiazide diuretics, while also sulfonamide-based, can produce similar allergic responses in susceptible patients. Spironolactone is a potassium-sparing diuretic that does not have the same chemical structure as sulfa drugs and is generally considered safer for individuals with a sulfa allergy. Acetazolamide, another diuretic, is also not a sulfonamide and is typically avoided in patients with sulfa allergies due to similar concerns.

Thus, furosemide's relative chemical structure and its association with sulfonamides make it a diuretic that is specifically contraindicated in patients with a sulfa allergy.