A 45-year-old woman presents with episodic headache, sweating, and palpitations. Her 24-hour urine metanephrines are elevated. CT scan shows a 4 cm right adrenal mass. Before surgical resection, which sequence of medical preparation is correct?
- A Beta-blockade first (propranolol), then alpha-blockade
- B Calcium channel blocker alone is adequate preoperative preparation
- C Alpha-blockade first (phenoxybenzamine), then beta-blockade after adequate alpha-blockade ✓
- D Simultaneous alpha and beta blockade from day 1
Correct answer: C. Alpha-blockade first (phenoxybenzamine), then beta-blockade after adequate alpha-blockade
Explanation
In pheochromocytoma, alpha-blockade must precede beta-blockade to prevent unopposed alpha-mediated vasospasm leading to hypertensive crisis. Phenoxybenzamine (non-selective, irreversible alpha-blocker) is started at least 7-14 days before surgery; only after adequate alpha-blockade is achieved can a beta-blocker be added to control tachycardia. Starting beta-blockade first blocks the beta2-mediated vasodilation, leaving alpha-mediated vasoconstriction unopposed — a potentially lethal sequence.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
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Written and medically reviewed by the StethoPrep medical team.