Which diuretic is commonly used to manage edema in CKD and what is a major side effect to monitor?

• A. Thiazide diuretics; monitor for hyperkalemia.
• B. Osmotic diuretics; monitor for hyponatremia.
• C. Loop diuretics (e.g., furosemide); monitor for hypokalemia and dehydration.
• D. Potassium-sparing diuretics; monitor for hyponatremia.

Answer: (C)

Controlling fluid overload in CKD relies on a diuretic that stays effective even when kidney filtration is reduced. Loop diuretics, such as furosemide, act on the Na-K-2Cl transporter in the thick ascending limb of the loop of Henle, producing a strong diuresis and natriuresis that help mobilize edema despite diminished GFR. Because they cause significant fluid and electrolyte loss, the major side effects to monitor are hypokalemia and dehydration. Low potassium can lead to muscle weakness and potential cardiac rhythm changes, and volume depletion can cause low blood pressure and further kidney stress. Close monitoring of electrolytes, kidney function, intake and output, and overall volume status is essential when using these agents. Other diuretics are less reliable in advanced CKD edema and have different risk profiles (for example, thiazides are less effective with low GFR and can still cause electrolyte shifts, osmotic diuretics are used for other indications and can cause hyponatremia, and potassium-sparing diuretics carry a risk of hyperkalemia).