Phentolamine is a non-selective, reversible alpha-adrenergic antagonist used primarily to treat hypertensive crises, pheochromocytoma-related hypertension, and to manage extravasation of vasoconstrictors. By blocking both alpha-1 and alpha-2 receptors, it induces vasodilation, reduces peripheral resistance, and lowers blood pressure, providing rapid control in acute settings. Developed in the 1950s, phentolamine was one of the first reversible alpha blockers, representing a significant advancement in cardiovascular pharmacology by offering a short-acting option for managing sympathetic overactivity. Beyond hypertension, it has also been employed in diagnostic testing for pheochromocytoma and, in combination with other agents, for the treatment of erectile dysfunction. Its introduction highlighted the therapeutic potential of reversible alpha blockade, allowing more precise and controllable management of conditions associated with excessive catecholamine activity.
