Aldosterone Antagonists

What are aldosterone antagonists?

Aldosterone antagonists, or aldosterone receptor antagonists, are prescription drugs that work against aldosterone, a hormone your adrenal glands make. These drugs are sometimes called mineralocorticoid receptor antagonists (MRAs) or potassium-sparing diuretics.

Your body uses the aldosterone it makes to raise your blood pressure when necessary. However, people who already have high blood pressure or are retaining excess fluid because of heart failure can benefit from aldosterone antagonists that keep aldosterone from working, helping to lower your blood pressure.

What drugs are aldosterone antagonists?

Aldosterone antagonist examples are:

• Spironolactone (Aldactone® and CaroSpir®): Tablet or liquid you swallow once a day with or without food. The U.S. Food and Drug Administration (FDA) approved the tablets in 1960 and then the liquid in 2017. Spironolactone is also available in combination with hydrochlorothiazide, a diuretic.
• Eplerenone (Inspra®): Tablet you swallow once or twice a day with or without food. FDA gave its approval in 2002.
• Finerenone (Kerendia®): Tablet you swallow once a day with or without food. FDA approved this drug in 2021 for chronic kidney disease associated with Type 2 diabetes.

What do aldosterone antagonists do?

Aldosterone antagonists (mineralocorticoid receptor antagonists) make your kidneys move extra water and salt into your pee so they’re out of your body. They do this while preventing you from losing potassium, which aldosterone makes your kidneys eliminate.

They work by blocking the receptor for the hormone aldosterone, which your body makes. Aldosterone makes your kidneys hold on to salt and water, which raises your blood pressure. Aldosterone is one of the ways your body adjusts blood pressure naturally in your blood vessels.

When you take an aldosterone blocker, your kidneys are able to release excess water and salt from your blood. The extra water and salt come out in your pee.

Why are aldosterone antagonists used in heart failure?

Fluids build up in people who have heart failure because their hearts aren’t able to pump blood the way they should. Aldosterone antagonists help people with heart failure get rid of excess fluid in their bodies. When there’s less fluid to pump, it’s easier on your heart.

What do aldosterone antagonists treat?

Aldosterone antagonists treat several medical conditions, including:

• Heart failure.
• High blood pressure that doesn’t improve with other medicines.
• Hyperaldosteronism.
• Edema (fluid retention) from liver or kidney disease.
• Chronic kidney disease.
• Low potassium level.
• Left ventricular dysfunction (problem with your heart’s primary pumping chamber) and heart failure or diabetes after a heart attack.
• Acne (typically prescribed by dermatologists).

How common are aldosterone antagonists?

Spironolactone is one of the top 100 prescribed medicines in the United States.

What are the advantages of aldosterone antagonists?

Aldosterone antagonists help people get excess water and salt out of their bodies without losing potassium. They help people with heart failure:

• Live longer.
• Exercise more than they could before.
• Have a better quality of life with improved symptoms.
• Spend less time in the hospital.

People with acute (happening now) heart failure have more than 1 million hospital stays a year in the United States. About half of them will be admitted to the hospital again or will pass away within six months of their hospital stay. Aldosterone antagonists can lower the risk of sudden cardiac death by about 20% in people who have heart failure and/or a problem with the left ventricle of their heart.

What are the possible side effects of aldosterone antagonists?

Like other diuretics, aldosterone antagonists will make you pee more often than usual.

Other side effects of aldosterone antagonists may include:

• Cough.
• Dizziness.
• Headache.
• Diarrhea.
• High potassium levels, especially for people with kidney disease. (In these cases, people should start at a lower dose, increasing the dosage gradually if the potassium level remains in a safe range.)

Because spironolactone may affect other types of receptors (androgen and progesterone) in your body, it may also cause:

• Enlarged breasts, regardless of gender.
• Erection problems.
• Vaginal bleeding after menopause.

For this reason, some people with heart failure want to take eplerenone instead. However, a number of studies have found that spironolactone works better. Also, spironolactone costs less than eplerenone.

How quickly do aldosterone antagonists work?

It may take several weeks for aldosterone antagonist drugs to reach their full effectiveness.

When should I see my healthcare provider?

Contact your healthcare provider if you’re having a hard time with the side effects of an aldosterone blocker. Your provider may be able to adjust your dose or switch you to a different brand. You should also let them know if you’ve been taking aldosterone antagonist drugs for a few weeks but your symptoms aren’t better.

A note from Cleveland Clinic

Whenever you get a new prescription, tell your healthcare provider what prescriptions you’re already taking. They’ll also want to know about supplements or herbs you take. Follow the instructions that come with your prescription medicine. The label should tell you how much to take and when to take it. It’s best to take medicine consistently, so take it at the same time of day each day. This helps you remember to take it. Don’t take two doses at a time to make up for one you forgot. Ask your provider before drinking grapefruit juice or using salt alternatives that may contain potassium.