• In a 54-year-old man with a norepinephrine-secreting pheochromocytoma, resistance developed to the α-adrenergic blocking agent, phenoxybenzamine hydrochloride. Dosages of 240 mg/day were ineffective. Intravenous phentolamine mesylate reduced his BP at first, but resistance developed to this also. Therapy with α-methylparatyrosine, an inhibitor of catecholamine biosynthesis, finally controlled his BP, and the tumor was removed.
(Arch Intern Med 1983;143:2321-2323)
Hauptman JB, Modlinger RS, Ertel NH. Pheochromocytoma Resistant to a-Adrenergic Blockade. Arch Intern Med. 1983;143(12):2321-2323. doi:10.1001/archinte.1983.00350120115025