in a prospective study designed to differentiate pheochromocytoma from other forms of hypertension , urinary catecholamines were measured after sleep and clonidine administration in 12 patients with pheochromocytoma , 19 hypertensive patients in whom pheochromocytoma was suspected but later excluded , and 31 hypertensive patients in whom pheochromocytoma was never suspected .
C0020538
hypertension
C0009014
clonidine