Spironolactone belongs to a class of medications called Mineralocorticoid Receptor Antagonist (MRA). It works on your kidneys to remove extra water and salts in your body. This will decrease the pressure on the blood vessels and allow the heart to work less hard. It is also used to reduce the amount of fluid present in the lungs as a result of heart failure.
Heart failure is a condition where the heart is weak and is unable to pump enough blood to the rest of the body. This medication is used in heart failure to improve the survival rate, reduce the symptoms of heart failure such as breathlessness or leg swelling and reduce the chance of being admitted to the hospital because of heart failure.
This medication may also be used to treat high blood pressure or high aldosterone (a type of hormone) levels.