Which combination of medications can cause hyperkalemia?

• A. Potassium-sparing diuretics and ACE inhibitors
• B. Loop diuretics and thiazides
• C. Beta blockers
• D. Calcium channel blockers

Answer: (A)

Hyperkalemia happens when the body’s ability to eliminate potassium is overwhelmed, often due to medications that promote potassium retention. Potassium-sparing diuretics reduce potassium excretion in the distal nephron, so more potassium stays in the body. ACE inhibitors decrease aldosterone production, and aldosterone normally helps the kidneys excrete potassium; with less aldosterone, potassium retention increases. Together, these two drug effects can raise serum potassium levels enough to cause dangerous arrhythmias, especially in patients with kidney impairment or those taking other potassium-raising factors. The other options either promote potassium loss (loop diuretics and thiazides) or don’t typically cause significant hyperkalemia on their own (beta blockers and calcium channel blockers). Monitor potassium and kidney function when these meds are used, particularly in combination.