Spironolactone is a synthetic 17-spironolactone corticosteroid with potassium-sparing diuretic, antihypertensive, and antiandrogen activities.Spironolactone competitively inhibits adrenocortical hormone aldosterone activity in the distal renal tubules, myocardium, and vasculature. This agent may inhibit the pathophysiologic effects of aldosterone produced in excess by various types of malignant and benign tumors. Rapidly and extensively metabolized. The metabolic pathway of spironolactone is complex and can be divided into two main routes: those in which the sulfur moiety is retained and those in which the sulfur moiety is removed by dethioacetylation. Spironolactone is transformed to a reactive metabolite that can inactivate adrenal and testicular cytochrome P450 enzymes. It also has anti-androgenic activity. Spironolactone is a specific pharmacologic antagonist of aldosterone, acting primarily through competitive binding of receptors at the aldosterone-dependent sodium-potassium exchange site in the distal convoluted renal tubule. Spironolactone causes increased amounts of sodium and water to be excreted, while potassium is retained. Spironolactone acts both as a diuretic and as an antihypertensive drug by this mechanism. It may be given alone or with other diuretic agents which act more proximally in the renal tubule. Aldosterone interacts with a cytoplasmic mineralocorticoid receptor to enhance the of the Na+, K+-ATPase and the Na+ channel involved in a Na+ K+ transport in the distal tubule. Spironolactone bind to this mineralcorticoid receptor, blocking the actions of aldosterone on gene . Aldosterone is a hormone; its primary function is to retain sodium and excrete potassium in the kidneys. | 
