Which diuretic is commonly used for edema due to heart failure?

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

Answer: (A)

Potent loop diuretics are the go-to for edema from heart failure because they cause large, rapid volume loss by blocking Na-K-2Cl reabsorption in the thick ascending limb of the loop of Henle. This produces strong natriuresis and diuresis, which quickly lowers preload and relieves pulmonary and systemic congestion that headaches or swelling indicate in heart failure. Furosemide is a classic loop diuretic used precisely for this reason: it acts quickly (oral onset about 30–60 minutes, IV in minutes) and remains effective even when kidney function is stressed, offering adjustable diuresis as needed.

Hydrochlorothiazide, a thiazide, works later in the nephron and provides more modest diuresis; it’s less reliable for significant edema in heart failure and is often not sufficient on its own for rapid relief, though it can be used as an adjunct. Spironolactone helps by blocking aldosterone and can improve outcomes in heart failure, but it’s a potassium-sparing diuretic with milder diuretic effects, used more for grading remodeling and mortality benefit rather than as the primary agent for acute edema. Acetazolamide inhibits carbonic anhydrase and yields only modest diuresis with a different clinical niche, not for managing edema in heart failure.

So, the best choice for edema due to heart failure is the loop diuretic that provides strong, rapid diuresis, with furosemide being the classic example.