A nurse is providing instruction to a new nurse about caring for clients who are receiving diuretic therapy to treat heart failure. The nurse should explain that which of the following medications puts clients at risk for both hyperkalemia and hyponatremia?

Choice A reason: Furosemide is a loop diuretic that promotes the excretion of sodium, potassium, and water. It commonly causes hypokalemia and hyponatremia, not hyperkalemia. Choice B reason: Metolazone is a thiazide-like diuretic that increases sodium and potassium excretion. It is associated with hypokalemia and hyponatremia, not hyperkalemia. Choice C reason: Hydrochlorothiazide, a thiazide diuretic, also promotes sodium and potassium loss, leading to hypokalemia and hyponatremia. It does not cause hyperkalemia. Choice D reason: Spironolactone is a potassium-sparing diuretic that blocks aldosterone, leading to sodium excretion and potassium retention. This mechanism increases the risk of hyperkalemia and hyponatremia, especially in clients with renal impairment or when used with other potassium-retaining agents.