The US Food and Drug Administration (FDA) has approved clonidine for the treatment of attention deficit hyperactivity disorder (ADHD), alone or with stimulants in 2010, for pediatric patients aged 6-17 years [REF].
Clonidine's effect on reducing circulating epinephrine by a central mechanism was used in the past as an investigatory test for phaeochromocytoma, which is a catecholamine-synthesizing tumour, usually of the adrenal medulla [REF].