Question:medium
Which of the following is false about pheochromocytoma?
Which of the following is false about pheochromocytoma?
Show Hint
In pheochromocytoma, using a beta-blocker alone without prior alpha blockade leads to a dangerous paradoxical rise in blood pressure.
Updated On: Jun 23, 2026
- Propranolol is preferred drug for hypertension control
- Surgery is treatment of choice
- VMA are diagnostic test
- Catecholamines are diagnostic test
Show Solution
The Correct Option is A
Solution and Explanation
Pheochromocytoma - systematic review of all options:
Pheochromocytoma secretes excess catecholamines (epinephrine, norepinephrine) causing hypertensive crises.
Drug management hierarchy (pre-operative):
Why propranolol alone is dangerous: Beta-2 blockade removes vasodilation, leaving alpha-1 mediated vasoconstriction unopposed $\Rightarrow$ paradoxical hypertensive crisis.
Diagnostic tests - TRUE facts:
The FALSE statement is that propranolol is the preferred drug for hypertension control.
\[\boxed{\text{Option A: Propranolol is preferred drug (FALSE)}}\]
Pheochromocytoma secretes excess catecholamines (epinephrine, norepinephrine) causing hypertensive crises.
Drug management hierarchy (pre-operative):
- $\textit{Alpha blockade FIRST}$: Phenoxybenzamine (non-selective alpha blocker) - given 1-2 weeks pre-op to control BP and expand volume.
- $\textit{Beta blockade SECOND}$ (only after alpha blockade): To control tachycardia.
Why propranolol alone is dangerous: Beta-2 blockade removes vasodilation, leaving alpha-1 mediated vasoconstriction unopposed $\Rightarrow$ paradoxical hypertensive crisis.
Diagnostic tests - TRUE facts:
- 24-hour urinary VMA (vanillylmandelic acid): TRUE - classic screening test
- Urinary/plasma catecholamines and metanephrines: TRUE - most sensitive tests
- Surgery (adrenalectomy): TRUE - definitive treatment
The FALSE statement is that propranolol is the preferred drug for hypertension control.
\[\boxed{\text{Option A: Propranolol is preferred drug (FALSE)}}\]
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