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Discussion Starter · #1 ·
A 24-year-old woman, who was diagnosed recently with pheochromocytoma, presents to the ER with high blood pressure. Treatment with phentolamine is initiated. Heart rate monitoring shows tachycardia because of this treatment.
What is the mechanism of action of phentolamine in this case?
A- Blockade of cholinergic receptors
B- Blockade of alpha-adrenergic receptors
C- Blockade of beta-adrenergic receptors
D- Direct vasoconstriction of blood vessels
E- Stimulation of adrenal gland to release epinephrine
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