Comparative Evaluation of Loop and Potassium-Sparing Diuretics in Heart Failure: Mechanisms, Clinical Roles, and Outcomes

Heart failure management frequently relies on diuretic therapy to alleviate congestion and optimize volume status. Loop diuretics, such as furosemide and torsemide, act on the Na⁺–K⁺–2Cl⁻ cotransporter in the loop of Henle and provide rapid, potent natriuresis. However, prolonged use may lead to electrolyte imbalance, neurohormonal activation, and diuretic resistance. Potassium-sparing diuretics, including aldosterone antagonists (spironolactone, eplerenone, finerenone) and ENaC blockers (amiloride, triamterene), act distally to conserve potassium and counteract aldosterone-driven sodium retention. When used together, these agents provide complementary effects. loop diuretics achieve effective decongestion while MRAs improve survival by mitigating cardiac remodeling. Major trials such as RALES and EPHESUS have established the mortality benefit of MRAs in heart failure. Careful monitoring of renal function and electrolytes remains essential to balance efficacy and safety.