In the management of pheochromocytoma prior to tumor removal, which sequence of medications is recommended to control blood pressure and tachycardia?

• A. Beta-blockers first, then alpha-blockers
• B. Alpha-blockers first, then beta-blockers
• C. ACE inhibitors first, then diuretics
• D. Diuretics first, then ACE inhibitors

Answer: (B)

In pheochromocytoma, the elevated catecholamines cause blood pressure mainly through alpha-adrenergic vasoconstriction and cause tachycardia through beta-adrenergic stimulation. The safe preoperative strategy is to block alpha receptors first to prevent the surge of vasoconstriction, then add a beta-blocker to control the heart rate and contractility once blood pressure is stabilized. Starting with a beta-blocker alone can remove beta-mediated effects while leaving alpha-mediated vasoconstriction unchecked, which may precipitate a dangerous hypertensive crisis. Therefore, alpha-blockade is established first (with agents like phenoxybenzamine or doxazosin) to achieve good BP control and allow volume expansion, and only after adequate alpha-blockade is achieved is a beta-blocker added to manage tachycardia. ACE inhibitors or diuretics are not the primary sequence for this scenario and do not address the dominant vasoconstrictive drive from alpha stimulation.