Which medication is indicated for preoperative therapy in a patient with an adrenal mass leading to symptoms of catecholamine excess?

In patients with an adrenal mass causing symptoms of catecholamine excess, such as those seen in pheochromocytoma, the primary goal is to manage hypertension and prevent catecholamine-related complications prior to surgical removal of the tumor. Phenoxybenzamine is an irreversible alpha-adrenergic antagonist that is specifically indicated for this purpose.

By blocking alpha-adrenergic receptors, phenoxybenzamine helps to reduce vasoconstriction and lowers blood pressure, effectively countering the effects of excessive catecholamines in the body. This cardiovascular stabilization is critical before surgery, as it minimizes the risk of hypertensive crises during and post-operation, which could arise from sudden release of catecholamines during tumor manipulation.

The other medications listed serve different purposes. Enalapril and losartan are primarily used for managing hypertension but do not specifically address the issue of catecholamine excess. Propranolol, a beta-blocker, could be considered to manage tachycardia associated with catecholamine excess; however, it is essential to use phenoxybenzamine first because the blockade of beta-adrenergic receptors can lead to unopposed alpha-agonism if not adequately addressed, potentially exacerbating hypertension. Thus, the use