Which medication in the elderly patient’s regimen is a potassium-sparing diuretic?

• A. Spironolactone
• B. Furosemide
• C. Ramipril
• D. Bisoprolol

Answer: (A)

Spironolactone is the potassium-sparing diuretic here. It works as an aldosterone receptor antagonist in the collecting ducts of the kidney. Aldosterone promotes sodium reabsorption and potassium excretion, so blocking its action reduces sodium reabsorption and increases water excretion while conserving potassium. In elderly patients, this potassium-sparing effect is helpful, but it requires monitoring of potassium and kidney function because hyperkalemia risk rises, especially if combined with other agents that raise potassium (like ACE inhibitors) or in reduced renal function. Furosemide is a loop diuretic that increases potassium loss. Ramipril is an ACE inhibitor that can raise potassium but is not a diuretic. Bisoprolol is a beta-blocker with no diuretic effect.