Aldactone (generic: spironolactone) is a prescription medication used to treat high blood pressure and fluid retention caused by various conditions. It is also used to treat low potassium levels and to diagnose and treat primary hyperaldosteronism, a condition in which the body produces too much of the hormone aldosterone.

This medication belongs to a group of drugs called diuretics ("water pills"). Specifically, it is a "potassium-sparing" diuretic known as an "aldosterone antagonist". By blocking aldosterone, Aldactone helps the body get rid of excess fluid  by increasing the amount of salt and water the kidneys remove from the blood, while still keeping potassium in the body. 

This medication comes in tablet form and is usually taken once or twice daily. Aldactone can be taken with or without food.

Common side effects of Aldactone include headache, nausea, and tiredness. Aldactone may cause drowsiness. Do not drive or operate heavy machinery until you know how it affects you.