phentolamine test

phen·tol·a·mine test

a test for pheochromocytoma; intravenous administration of phentolamine (5 mg) reduces hypertension due to a pheochromocytoma but not that due to other causes, for example, essential hypertension; the blood pressure is raised by the drug in the latter form of hypertension.

phentolamine test

A pharmacologic test for pheochromocytoma, in which an α-adrenergic blocker, phentolamine, is administered IV; a significant drop in bp, confirmed by quantifying catecholamines or their metabolites in the urine. See Catecholamines, Pharmacological testing.