Final Answer:
Phenoxybenzamine is a non-selective alpha-receptor antagonist used as an irreversible, long-acting antihypertensive. It is employed for the diagnostic and management purposes of Pheochromocytoma.
Step-by-step explanation:
Phenoxybenzamine, classified as a non-selective alpha-receptor antagonist, is employed in the management of conditions such as Pheochromocytoma. This rare adrenal tumor produces excessive amounts of catecholamines, leading to severe hypertension. Phenoxybenzamine acts by irreversibly binding to alpha receptors, preventing the vasoconstrictive effects of catecholamines. Due to its irreversible nature, the antihypertensive effect is prolonged, making it suitable for long-term blood pressure control.
In the context of Pheochromocytoma, Phenoxybenzamine plays a crucial role in both diagnostic and therapeutic aspects. Prior to surgical removal of the tumor, it is essential to control blood pressure to avoid hypertensive crises during the procedure. Phenoxybenzamine's non-selective blockade of alpha receptors helps achieve this by preventing the vasoconstrictive response to catecholamines released from the tumor. Additionally, by blocking these receptors, it helps manage symptoms such as excessive sweating and palpitations associated with Pheochromocytoma.
Phenoxybenzamine's irreversible binding to alpha receptors distinguishes it from other alpha-receptor antagonists, making it particularly suitable for the sustained control of hypertension associated with Pheochromocytoma. Its role in both diagnosis and treatment highlights its significance in the comprehensive management of this challenging condition.