Which medication is most commonly associated with hypokalemia in cardiovascular patients?

• A. Furosemide (Loop diuretic)
• B. Spironolactone
• C. ACE inhibitors
• D. Digoxin

Answer: (A)

The main idea is that drugs that increase potassium loss in the kidneys drive hypokalemia in cardiovascular patients. Loop diuretics like furosemide inhibit the Na-K-2Cl transporter in the thick ascending limb, so more sodium reaches the distal nephron. There, sodium reabsorption is coupled to potassium and hydrogen ion secretion, leading to increased potassium excretion and lower potassium levels. Volume depletion from diuresis also raises aldosterone, further boosting potassium loss.

Spironolactone and ACE inhibitors tend to raise potassium or prevent its loss, not cause depletion. Digoxin toxicity is worsened by low potassium, but digoxin itself doesn’t typically cause hypokalemia. So the medication most commonly linked to hypokalemia is the loop diuretic.