Potassium-sparing diuretics are used to treat high blood pressure, heart failure, and fluid retention (edema) for health conditions, such as kidney or liver disease. These medications work by helping your body get rid of excess salt and water while keeping potassium levels balanced. Potassium-sparing diuretics are usually taken as oral pills. Examples include amiloride (Midamor) and triamterene (Dyrenium).