Which diuretic is potassium-sparing and commonly used for edema in heart failure?

Which diuretic is potassium-sparing and commonly used for edema in heart failure?

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

Answer: (B)

Potassium-sparing diuretics that act as aldosterone antagonists are particularly useful in heart failure because they counteract the sodium-retaining effects of aldosterone without depleting potassium. Spironolactone blocks the mineralocorticoid receptor, so aldosterone can’t promote sodium reabsorption in the late distal tubule and collecting duct. This leads to more sodium and water being excreted while potassium is preserved. In heart failure, aldosterone levels are often high, driving fluid retention and adverse remodeling; by antagonizing this hormone, spironolactone not only helps reduce edema but also provides survival benefits when added to standard heart failure therapy. Other diuretics, like thiazides or loop diuretics, tend to cause potassium loss, and acetazolamide isn’t used for heart-failure edema because it has a different mechanism and isn’t potassium-sparing. That's why spironolactone is the preferred potassium-sparing option for edema in heart failure.

Potassium-sparing diuretics that act as aldosterone antagonists are particularly useful in heart failure because they counteract the sodium-retaining effects of aldosterone without depleting potassium. Spironolactone blocks the mineralocorticoid receptor, so aldosterone can’t promote sodium reabsorption in the late distal tubule and collecting duct. This leads to more sodium and water being excreted while potassium is preserved. In heart failure, aldosterone levels are often high, driving fluid retention and adverse remodeling; by antagonizing this hormone, spironolactone not only helps reduce edema but also provides survival benefits when added to standard heart failure therapy. Other diuretics, like thiazides or loop diuretics, tend to cause potassium loss, and acetazolamide isn’t used for heart-failure edema because it has a different mechanism and isn’t potassium-sparing. That's why spironolactone is the preferred potassium-sparing option for edema in heart failure.