In the context of a pheochromocytoma, why must an alpha-blocker be administered before a beta-blocker?
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Correct answer: To prevent unopposed alpha-mediated vasoconstriction and a hypertensive crisis
If beta-receptors are blocked first, the vasodilatory beta-2 receptors are unavailable. The massive amount of circulating catecholamines from the tumor would then act solely on alpha-1 receptors, leading to severe, life-threatening vasoconstriction.
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