A 38-year-old man with a biochemically confirmed pheochromocytoma is scheduled for laparoscopic adrenalectomy. Blood pressure is 170/105 mmHg on two agents. Which drug must be established before beta blocker therapy to avoid precipitating a hypertensive crisis intraoperatively?
- A Phenoxybenzamine ✓
- B Propranolol
- C Metyrosine
- D Nicardipine
Correct answer: A. Phenoxybenzamine
Explanation
Alpha adrenergic blockade must precede beta blockade because unopposed alpha stimulation after beta blockade can cause severe vasoconstriction and hypertensive crisis. Phenoxybenzamine, an irreversible nonselective alpha blocker, is the classic preoperative agent, given for 10 to 14 days before surgery along with salt and fluid loading. Propranolol is added only after adequate alpha blockade, making it a distractor rather than an answer.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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