This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology and breast, Subject name: Surgery
Treatment of hypeensive crisis in pheochromocytoma 
Select and explain. 
A. Phentolamine, B. Hydralazine, C. Guanethidine, D. Salameterol
A: Phentolamine
Answer: A: Phentolamine 
Explanation: Ref:KD Tripathi 7thE pg: 565 Phentolamine is used for pheochromocytoma. Note Non selective alfa-blockers cause fall in t.p.r, which is compensated by increased HR and C.O. So, they are not used routinely for htn. They block both alfa-1 and alfa-2 receptors- NA release is accentuated. Reserved for special situations like pheochromocytoma, clonidine withdrawal, cheese reaction, where circulating CA&;s are responsible for the rise in BP.