Question

Drug of choice for pheochromocytoma during surgery is:

• A. Phentolamine
• B. Phenoxybenzamine
• C. Propranolol
• D. Prazosin

Hint:

Think about which alpha blocker has a short, titratable action suitable for acute intraoperative use.

Answer 1

The Correct Option is A

Step 1: Understand the pharmacological challenge during pheochromocytoma surgery.
Pheochromocytoma releases catecholamines (adrenaline and noradrenaline) in large bursts, especially during surgical manipulation of the tumor. This causes severe, life-threatening hypertensive crises intraoperatively that must be controlled immediately.

Step 2: Distinguish preoperative from intraoperative management.

• Preoperative: Phenoxybenzamine (long-acting, non-selective, irreversible alpha blocker) is used for 10-14 days before surgery to achieve steady alpha-blockade.
• Intraoperative: Phentolamine (short-acting, reversible, competitive alpha blocker) is the drug of choice for acute hypertensive surges during surgery. It can be given as IV bolus or infusion and its effect wears off quickly, allowing rapid titration.

Step 3: Why not propranolol or prazosin intraoperatively?
Propranolol (beta blocker) is used only after adequate alpha blockade is established; using it alone causes unopposed alpha stimulation and worsens hypertension. Prazosin (selective alpha-1 blocker) is used in preoperative preparation but not intraoperatively. Phenoxybenzamine's irreversible action is too long-lasting for acute intraoperative titration.

Conclusion: Phentolamine is the drug of choice during pheochromocytoma surgery for acute intraoperative hypertensive episodes.