Blood Pressure Drugs - Aldosterone Antagonists

How do aldosterone antagonists work?

Aldosterone is a hormone that causes the body to retain salt and water. Certain cells in the body have special receptors for aldosterone. Aldosterone antagonists block these receptors in the kidneys, heart, blood vessels, and brain. This triggers the body to get rid of more salt and water in the form of urine. This reduces the volume of blood in the body, lowering blood pressure.

Who should take aldosterone antagonists?

Aldosterone antagonists work well at reducing blood pressure in patients with mild to moderate high blood pressure, particularly when combined with ACE inhibitors or ARBs. They may also be useful in treating heart failure after a heart attack.^{5, 6}

Older aldosterone blockers (such as spironolactone) also block other hormone receptors that can cause problematic side effects, including lowering of the voice or excessive hair growth in women and men, or enlarged breasts in men. A new class of drugs called selective aldosterone-receptor antagonists (SARAs) block only aldosterone receptors, resulting in fewer side effects. The first of these drugs, eplerenone (Inspra), was approved by the FDA to treat high blood pressure in 2002. Since these drugs are fairly new, it is not yet known which patients benefit the most, so they are usually used only in patients who still have high blood pressure after trying other types of blood pressure drugs.

What side effects do aldosterone antagonists have?

One possible side effect of aldosterone antagonists is the development of high potassium in the blood ( hyperkalemia), which can have dangerous effects on heart function. If you are on this drug, your doctor will monitor you for this condition. Lowering the dose usually eliminates this side effect.