... A nonselective alpha-adrenergic antagonist. It is used in the treatment of hypertension and Name: Phentolamine mesilate, Phentolamine mesylate, Phentolamine hcl, Phentolamine hydrochloride ... alpha-adrenergic antagonist. It is used in the treatment of hypertension and hypertensive emergencies, pheochromocytoma, vasospasm of raynaud disease and frostbite, clonidine withdrawal syndrome, impotence ...