All the following drugs are used in pheochromocytoma except?

Beta blockers will lead to unopposed alpha action leading to worsening of pre-existing vasoconstriction in pheochromocytoma. Thus the correct way to manage pheochromocytoma patients is to first initiate alpha blockade and then follow up with beta blockade. Metyrosine inhibits catecholamine production and is useful in malignant pheochromocytoma. Adequate alpha blockade generally requires 7 days, with a typical final dose of 20-30 mg phenoxybenzamine three times per day. HTN crisis might require sodium nitroprusside. Oral prazosin or intravenous phentolamine can be used to manage paroxysms while awaiting adequate alpha blockade. Before surgery, blood pressure should be consistently below 160/90 mmHg, with moderate ohostasis. Beta blockers (e.g., 10 mg propranolol three to four times per day) can be added after staing alpha blockers and increased as needed if tachycardia persists. Other antihypeensives, such as calcium channel blockers or angiotensin-conveing enzyme inhibitors, have been used when blood pressure is difficult to control with phenoxy-benzamine alone.