Spironolactone is a specific antagonist of the mineralocorticoid receptor in the distal tubules and collecting ducts of the kidney. Spironolactone counteracts the actions of aldosterone and thus has a natriuretic and potassium-sparing effect.
Spironolactone is often used in combination with other diuretics in the treatment of therapy resistant hypertension heart failure and edema. It is the drug of choice in the treatment of primary hyperaldosteronism and liver cirrhosis. In the later spironolactone has more efficacy compared to other diuretics, because the drug enters the cell by its basolateral membrane.
Because of its effect, spironolactone is usually categorised under the potassium sparing diuretics. And so is hyperkalemia the main adverse effect of spironolactone, especially in renal failure. Because of its steroid structure, spironolactone can interfere with other steroids and causing symptoms like gynaecomastia, impotence, hirsutism, and menstrual disturbances. GI complaints and CNS disturbances are similar as with other potassium sparing diuretics.
Which of the following drugs do NOT cause hyperkalemia?
Extra info: β-agonists such as salmeterol that can cause hypokalemia. Other drugs such as spironolactone, amiloride and triamterene are known to cause hyperkalemia.
What is spironolactone NOT used for?
Extra info: Acute renal insufficiency with a creatinine clearance < 25 ml/min is a contraindication for the use of spironolactone.