Which diuretic class is preferred for edema from heart failure and resistant hypertension?

• A. Thiazide diuretics
• B. Potassium-sparing diuretics
• C. Osmotic diuretics
• D. Loop diuretics

Answer: (D)

Understanding how diuretics remove fluid clarifies why loop diuretics are preferred for edema from heart failure and resistant hypertension. Loop diuretics act on the thick ascending limb of the loop of Henle and inhibit the Na-K-2Cl cotransporter, producing a brisk and potent diuresis. This strong fluid loss directly reduces circulating volume and venous return, easing edema and lowering preload—crucial benefits in heart failure. In resistant hypertension, volume overload often drives higher blood pressure, and the substantial diuretic effect of loop agents helps overcome this. They remain effective even when kidney function is reduced, which is common in heart failure, whereas thiazides rely on adequate GFR to work well. Potassium-sparing diuretics provide milder diuresis and mainly help with potassium balance, not edema control. Osmotic diuretics have different indications and aren’t standard for systemic edema from heart failure. So the class that best addresses the volume overload in both heart failure edema and resistant hypertension is loop diuretics.