This information is for people with heart failure. It tells you about aldosterone receptor antagonists, drugs used for heart failure. It is based on the best and most up-to-date research.
Do they work?
Yes. If you have heart failure, taking a drug called an aldosterone receptor antagonist will probably reduce your risk of dying of heart failure. It may also help to keep you out of hospital.
What are they?
Aldosterone receptor antagonists reduce the amount of fluid in your body by increasing the amount of urine that you produce. If you have heart failure, your body may hold on to too much water. Aldosterone receptor antagonists help to get rid of the extra water.
Aldosterone receptor antagonists are often used with other drugs called diuretics, which also help to get rid of extra water in your body.
Examples of aldosterone receptor antagonists are:
In the UK, aldosterone receptor antagonists are usually only used in people with moderate to severe heart failure.  Your doctor may prescribe one of these drugs if you've been taking other drugs for heart failure, such as ACE inhibitors or beta-blockers, but you still have bad symptoms. 
How can they help?
Taking an aldosterone receptor antagonist can cut your risk of dying of heart failure.   In a large review of the research looking at people with heart failure: 
Treatment also helped keep people out of hospital. 
However, most of the studies have lasted less than a year, so we can't be sure about the long-term benefits.
How do they work?
Aldosterone receptor antagonists block the action of aldosterone, a chemical that regulates the balance of salt and water in your body. Blocking the action of aldosterone reduces the amount of fluid in your body by increasing the amount of urine you produce. Reducing the fluid in your body should make you more comfortable.
Aldosterone receptor antagonists also block the effects of some other chemicals that are made by your body. One of these, adrenaline, can put your heart under stress by making it beat faster and more strongly.