Which diuretic class is typically used to reduce edema in congestive heart failure?

• A. Loop diuretics
• B. Thiazide
• C. Potassium-sparing diuretics
• D. Carbonic anhydrase inhibitors

Answer: (A)

Loop diuretics are used to reduce edema in congestive heart failure because they are the most potent and rapid-acting class for removing excess fluid. They work by inhibiting the Na+-K+-2Cl- cotransporter in the thick ascending limb of the loop of Henle, leading to large amounts of salt and water being excreted. This quickly lowers preload and alleviates peripheral and pulmonary edema, which is critical in heart failure management. While thiazides can help with milder edema or be added for a stronger effect, they’re not as effective for significant edema as loop diuretics. Potassium-sparing diuretics provide weaker diuresis and are mainly used to conserve potassium or as adjuncts, and carbonic anhydrase inhibitors yield limited diuresis and aren’t used to treat CHF edema. Therefore, the best choice is loop diuretics, with furosemide being a common example.