Which diuretic is a loop diuretic used to rapidly relieve edema in heart failure?

• A. Hydrochlorothiazide
• B. Spironolactone
• C. Acetazolamide
• D. Furosemide

Answer: (D)

Edema relief in heart failure needs a diuretic that acts quickly and strongly to remove salt and water. Loop diuretics fit this need because they block the Na-K-2Cl cotransporter in the thick ascending limb of the loop of Henle, causing a large amount of sodium and water to be excreted. That powerful natriuresis rapidly lowers circulating volume and preload, which directly reduces edema and symptom burden in heart failure. Furosemide is the classic loop diuretic used for this rapid relief, including in acute settings, and its effect is appreciable even when kidney function isn’t perfect. By contrast, other diuretics act more weakly or more slowly: a thiazide like hydrochlorothiazide is less potent and slower in edema, spironolactone is potassium-sparing with longer onset and is used for longer-term management and mortality benefit, and acetazolamide is a weaker diuretic not ideal for rapid edema relief.