Spironolactone is a medicine used to lower high blood pressure or to treat heart failure. Because this medicine functions as a potassium-sparing diuretic, it is also referred to as a water pill. Its benefits of reducing blood pressure also help deter other central nervous system conditions.
Spironolactone is typically taken by mouth. Other conditions it is used to treat include low potassium and excessive production of a chemical in the body called aldosterone. Upset stomach is a common side effect, so it is normally advised to take this medicine with food or milk. Because it can also lead to urination, people are advised to take the pill early in the day.