ATC Group: C03D Potassium-sparing agents

Amiloride has mild diuretic and anti-hypertensive activity. It acts primarily in the distal tubule and does not require aldosterone for its action. Amiloride is a mild natriuretic which does not initiate a concomitant decrease in potassium levels.

Eplerenone has relative selectivity in binding to recombinant human mineralocorticoid receptors compared to its binding to recombinant human glucocorticoid, progesterone and androgen receptors. Eplerenone prevents the binding of aldosterone, a key hormone in the renin-angiotensin-aldosterone-system (RAAS), which is involved in the regulation of blood pressure and the pathophysiology of CV disease.

Finerenone is a nonsteroidal, selective antagonist of the mineralocorticoid receptor (MR) which is activated by aldosterone and cortisol and regulates gene transcription. Its binding to the MR leads to a specific receptor-ligand complex that blocks recruitment of transcriptional coactivators implicated in the expression of pro-inflammatory and pro-fibrotic mediators.

Spironolactone, as a competitive aldosterone antagonist, increases sodium excretion whilst reducing potassium loss at the distal renal tubule. It has a gradual and prolonged action.

Triamterene is a potassium-sparing agent. Triamterene inhibits the reabsorption of sodium ions in exchange for potassium and hydrogen ions at that segment of the distal tubule under the control of adrenal mineralocorticoids (especially aldosterone). The fraction of filtered sodium reaching this distal tubular exchange site is relatively small, and the amount which is exchanged depends on the level of mineralocorticoid activity. Thus, the degree of natriuresis and diuresis produced by inhibition of the exchange mechanism is necessarily limited.