<prompt> Treatment of hypeensive crisis in pheochromocytomaPhentolamineHydralazineGuanethidineSalameterol  <response>: 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. 