Which diuretic can be used in treatment of hypercalcemia?
**Core Concept**
The management of hypercalcemia involves reducing intestinal calcium absorption, increasing renal excretion of calcium, and inhibiting osteoclastic bone resorption. Loop diuretics are a key part of this strategy by promoting calcium excretion in the urine.
**Why the Correct Answer is Right**
Loop diuretics, such as furosemide, work by inhibiting the sodium-potassium-chloride cotransporter (NKCC2) in the thick ascending limb of the loop of Henle. This action leads to increased sodium and chloride delivery to the distal tubule, resulting in increased calcium excretion in the urine. By promoting calcium excretion, loop diuretics can help lower serum calcium levels and alleviate symptoms of hypercalcemia.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because thiazide diuretics actually increase calcium reabsorption in the distal convoluted tubule, which would worsen hypercalcemia.
**Option B:** This option is incorrect because beta-blockers are used to treat hypertension and certain arrhythmias, but they are not typically used to manage hypercalcemia.
**Option C:** This option is incorrect because aldosterone antagonists, such as spironolactone, primarily act in the collecting duct to inhibit sodium reabsorption and potassium secretion, and are not a first-line treatment for hypercalcemia.
**Clinical Pearl / High-Yield Fact**
When managing hypercalcemia, it's essential to remember that loop diuretics should be used in conjunction with other treatments, such as bisphosphonates or calcitonin, to effectively lower serum calcium levels.
**Correct Answer:** C. Furosemide