A 58-year-old man with decompensated heart failure needs a loop diuretic. He gives a clear history of severe generalized reaction to sulfonamide antibiotics. Which loop diuretic can be safely used?

• A Furosemide
• B Bumetanide
• C Torsemide
• D Ethacrynic acid ✓

Explanation

Ethacrynic acid is the only loop diuretic that is not a sulfonamide derivative, making it the agent of choice in documented sulfonamide allergy. Furosemide, bumetanide, torsemide and all thiazides contain a sulfonamide moiety. Ethacrynic acid carries the highest risk of ototoxicity among loop diuretics, so it is reserved for patients who truly cannot receive other loops.

Reference: Katzung Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.