Which medication is considered an aldosterone inhibitor?

Aldosterone inhibitors are a class of medications that block the action of aldosterone, a hormone produced by the adrenal glands that helps regulate sodium and potassium levels, as well as blood pressure. Spironolactone is widely recognized as an aldosterone antagonist, meaning it directly inhibits the effects of aldosterone on its receptors in the kidneys. This action leads to increased excretion of sodium and water while retaining potassium, which is particularly beneficial in conditions like heart failure, hypertension, and certain types of edema.

In contrast, the other medications listed do not function as aldosterone inhibitors. Furosemide is a loop diuretic that works by inhibiting the reabsorption of sodium and chloride in the kidneys but does not specifically target aldosterone. Metoprolol is a beta-blocker that primarily affects heart rate and blood pressure but does not have any direct action on aldosterone. Digoxin, on the other hand, is a cardiac glycoside used primarily in heart failure and arrhythmias, having no effect on aldosterone pathways. Thus, Spironolactone stands out as the sole aldosterone inhibitor among the options provided.