Pheochromocytoma is a rare, catecholamine (ex. adrenaline) secreting tumor that requires preoperative alpha blockade to minimize intraoperative hemodynamic instability, thereby reducing intra- and postoperative morbidity and mortality. Phenoxybenzamine is a non-selective alpha blocker that is significantly more expensive and is associated with increased adverse effects in comparison with selective alpha blockers such as doxazosin. Retrospective studies show minimal differences in hemodynamic instability and no differences in postoperative morbidity and mortality between selective vs. non-selective alpha blockers. This study is a randomized controlled trial that will compare hemodynamic instability, morbidity, mortality, cost, and quality of life between patients blocked with phenoxybenzamine vs. doxazosin.