What is the mechanism of action of aldosterone antagonists?

Aldosterone antagonists are primarily designed to block the effects of aldosterone, a hormone produced by the adrenal glands that plays a critical role in regulating sodium and potassium levels in the body. By antagonizing aldosterone, these medications inhibit the hormone's action on mineralocorticoid receptors located in the distal tubules and collecting ducts of the kidney. This antagonism prevents aldosterone from promoting sodium reabsorption and potassium excretion.

As a result, the use of aldosterone antagonists leads to increased excretion of sodium and water, thereby reducing blood volume and lowering blood pressure. They are commonly used in conditions such as heart failure and hypertension, where modulation of fluid and electrolyte balance is essential for management. This mechanism distinguishes aldosterone antagonists from other choices, which either represent opposing functions or actions related to different hormones and processes within the body.