Of the following diuretic medications, which conserves potassium?

Spironolactone is the diuretic medication that conserves potassium. It is classified as a potassium-sparing diuretic, which means it helps the body retain potassium while promoting the excretion of sodium and water. This is particularly important in patients at risk for hypokalemia, a condition characterized by low potassium levels, which can occur with other types of diuretics.

Unlike loop diuretics such as furosemide or thiazide diuretics like chlorthalidone and chlorothiazide, which can lead to an increase in potassium excretion and potentially result in hypokalemia, spironolactone counteracts this effect by antagonizing the action of aldosterone in the distal tubules of the kidney. This mechanism allows for sodium and water excretion while maintaining potassium levels in the bloodstream, making spironolactone particularly valuable in the management of conditions like heart failure, where potassium balance is crucial.