K+ sparing diuretics

Potassium-sparing diuretics play a distinctive role in managing fluid balance by promoting diuresis while helping to preserve potassium levels in the body. These medications target kidney's collecting tubule system, which is vital for sodium chloride resorption and ultimately regulates the body's fluid volume. The mineralocorticoid aldosterone, which plays a role in sodium reabsorption and volume retention, influences potassium excretion within the collecting duct by enhancing the activity of sodium-potassium pumps. This results in sodium retention and potassium secretion, and potassium-sparing diuretics disrupt these processes by blocking sodium influx and decreasing aldosterone production. For example, drugs like amiloride and triamterene block sodium entry through epithelial sodium channels (ENaC), leading to enhanced sodium and water excretion while preserving potassium levels in the body. Similarly, eplerenone and spironolactone directly antagonize the mineralocorticoid receptor, which effectively reduces sodium retention and limits potassium excretion. These interventions are helpful when dealing with conditions of excess mineralocorticoid activity, and offer a focused way to manage fluid and electrolyte balance.