Spire Indications/Uses

Spironolactone, a steroid with a structure resembling that of the natural adrenocortical hormone aldosterone, acts on the distal portion of the renal tubule as a competitive antagonist of aldosterone. It acts as a potassium-sparing diuretic, increasing sodium and water excretion and reducing potassium excretion.
Spironolactone is reported to have a relatively slow onset of action, requiring 2 or 3 days for maximum effect, and a similarly slow diminishment of action over 2 or 3 days on stopping.
Spironolactone is used in the management of heart failure, both to treat refractory oedema and in lower doses as an adjunct to standard therapy. It is also used for refractory oedema associated with cirrhosis of the liver or the nephrotic syndrome, and in ascites associated with malignancy. It is frequently given with the thiazides, furosemide, or similar diuretics, where it adds to their natriuretic but diminishes their kaliuretic effects, hence conserving potassium in those at risk from hypokalemia.
It has been used in the treatment of essential hypertension (in lower doses than for edema), but in the UK is no longer recommended for use in either essential hypertension or idiopathic edema; doubts have been expressed over its safety during long term administration.
Spironolactone is also used in the diagnosis and treatment of primary hyperaldosteronism. Other conditions in which spironolactone has been tried on the basis of its anti-androgenic properties include hirsutism, particularly in the polycystic ovary syndrome.