Trade name for Spironolactone. This is a moderately weak diuretic. Useful because it spares potassium – which must not get too low, and which may be driven low by other diuretics. Also its action as an aldosterone antagonist has in a round about way quite a marked influence on the progression of some myocardial diseases and it is becoming more and more popular in treatment of heart disease. It should not be used in any conditions which may cause hyperkalamia (too high potassium) such as Addisions disease and acute renal failure.