potassiumwparing

Potassium-sparing diuretics are a class of diuretics that promote urine production while conserving potassium in the distal parts of the kidney. They are used to treat hypertension, edema, and conditions associated with excess aldosterone or potassium loss from other diuretics.

There are two main subclasses. Mineralocorticoid receptor antagonists, such as spironolactone and eplerenone, block the action of aldosterone in the collecting ducts. This reduces sodium reabsorption and potassium excretion, helping to lower blood pressure and reduce fluid buildup. A second subgroup comprises epithelial sodium channel blockers, including amiloride and triamterene, which directly inhibit ENaC in the collecting ducts, decreasing sodium reabsorption and potassium loss.

Common clinical uses include management of hypertension, heart failure with reduced ejection fraction, hepatic cirrhosis with ascites, and certain forms of primary hyperaldosteronism. Spironolactone has additional roles in conditions such as resistant hypertension and, historically, edema from different causes; eplerenone is often chosen when endocrine side effects are a concern. Amiloride and triamterene are sometimes used in combination with thiazide or loop diuretics to prevent potassium loss.

Potential adverse effects center on hyperkalemia, especially when kidney function is impaired or when used with ACE inhibitors, ARBs, NSAIDs, or potassium supplements. Spironolactone can cause endocrine effects such as gynecomastia and menstrual irregularities; eplerenone generally has fewer such effects. Patients require monitoring of serum potassium and kidney function, with dose adjustments or discontinuation if potassium rises significantly.

Overall, potassium-sparing diuretics provide a useful option for diuresis with potassium conservation, but require careful patient selection and monitoring to mitigate risks.