Potassium-sparing diuretics reduce Na+ reabsorption and reduce K+ secretion in the distal part of the nephron (collecting tubule).• These are not potent diuretics when used alone; they are primarily used in combination with other diuretics.• Antagonists of the mineralocorticoid (aldosterone) receptor include eplerenone, which is highly receptor selective, and spironolactone, which binds to other nuclear receptors such as the androgen receptor.