What agent is primarily used for blood pressure control with pheochromocytoma?

The primary agent used for blood pressure control in pheochromocytoma is phenoxybenzamine. This medication is a non-selective, irreversible alpha-adrenergic antagonist that is particularly effective in managing the hypertension associated with pheochromocytoma. This condition involves the excessive production of catecholamines, which can lead to significant cardiovascular complications. Phenoxybenzamine works by blocking the action of these catecholamines at the alpha receptors, resulting in vasodilation and reduced blood pressure.

It is important to note that while the other medications can also play roles in managing hypertension, they do not specifically address the unique challenges posed by pheochromocytoma in the same way that phenoxybenzamine does. For example, labetalol and carvedilol are beta-blockers with some alpha-blocking properties that may be used in other hypertensive emergencies but are not the first-line choices for pheochromocytoma. Metoprolol, being a selective beta-blocker, would not adequately manage the hypertension driven by excessive alpha stimulation in pheochromocytoma. Therefore, phenoxybenzamine remains the preferred choice for its alpha-receptor antagonism and its role in reducing catecholamine-induced hypertension.