Spironolactone is a potassium-sparing diuretic used in which conditions?

• A. Liver failure with ascites to promote diuresis
• B. Hyperkalemia
• C. Acute kidney stones
• D. Hypertensive emergencies

Answer: (A)

Spironolactone blocks aldosterone action in the collecting ducts, so it acts as a potassium-sparing diuretic: it promotes sodium and water loss while retaining potassium. This makes it especially useful in conditions where aldosterone-driven fluid retention is a problem. In liver failure with ascites, cirrhosis causes secondary hyperaldosteronism, leading to sodium and water retention and fluid buildup. By antagonizing aldosterone, spironolactone reduces this retention and helps diurese the ascites without causing potassium loss. It’s not used to treat hyperkalemia—doing so would worsen potassium elevation—nor is it a first-line choice for acute kidney stones or hypertensive emergencies, where other agents are more appropriate for rapid or targeted effects.