Which pair of agents is associated with hypokalemia due to intracellular potassium shift by increasing Na+/K+ ATPase activity?

• A. Insulin and Epinephrine
• B. Aldosterone and Hydrocortisone
• C. Potassium chloride and Glucose
• D. Calcium and Magnesium

Answer: (A)

Potassium balance can change when the Na+/K+ ATPase pump is stimulated to move K+ into cells. Insulin promotes cellular uptake of potassium by activating this pump, so after insulin release or administration, K+ shifts from the blood into cells, lowering serum potassium. Epinephrine, acting on beta-2 receptors, increases cAMP and activates pathways that also boost Na+/K+ ATPase activity, producing a similar intracellular shift of potassium. Together, these agents can cause hypokalemia by pulling potassium into cells. Clinically, this is why insulin with glucose is used to acutely treat hyperkalemia, and beta-agonists can be used as adjuncts. In contrast, aldosterone and hydrocortisone mainly affect renal potassium excretion rather than driving intracellular shift; potassium chloride with glucose doesn’t specifically upregulate the pump; calcium and magnesium don’t primarily cause this intracellular potassium movement.