Which of the following is a known contributor to hyperkalemia?

• A. ACE inhibitors
• B. Spironolactone
• C. Beta-blockers
• D. All of the above

Answer: (D)

Potassium balance hinges on aldosterone-driven potassium excretion in the distal nephron. When this system is disrupted, serum potassium can rise.

ACE inhibitors lower angiotensin II, which reduces aldosterone production. With less aldosterone, the kidney excretes less potassium, raising the risk of hyperkalemia.

Spironolactone directly blocks aldosterone receptors in the collecting ducts, diminishing potassium excretion even if aldosterone is present. This potassium-sparing effect makes hyperkalemia more likely.

Beta-blockers can contribute by limiting beta-2–mediated cellular uptake of potassium, and they may also blunt insulin release, reducing potassium’s shift into cells. In patients with reduced kidney function, these effects are more pronounced and can tip potassium balance toward hyperkalemia.

Because each mechanism can elevate potassium, all of these agents are known contributors to hyperkalemia. Monitor potassium closely when using any of them, especially together or in patients with renal impairment.