Which of the following medications is an aldosterone inhibitor used in CHF?

Spironolactone is identified as an aldosterone inhibitor, which makes it particularly relevant in the management of congestive heart failure (CHF). Aldosterone is a hormone that promotes sodium and water retention, which can lead to increased blood volume and further exacerbate heart failure symptoms. By inhibiting aldosterone, spironolactone decreases fluid retention and decreases the strain on the heart, improving overall heart function and patient outcomes.

In the context of the other medications listed, prazosin is an alpha-1 antagonist primarily used for hypertension and to relieve urinary retention in benign prostatic hyperplasia. Hydrochlorothiazide is a thiazide diuretic that helps reduce blood pressure and manage edema but does not specifically inhibit aldosterone. Amiodarone is an antiarrhythmic medication used to treat various cardiac arrhythmias, but it does not function as an aldosterone antagonist. Thus, spironolactone stands out as the appropriate choice for its role as an aldosterone inhibitor specifically applied in CHF treatment.