Clonidine (CLD)

Clonidine is a sympatholytic medication used to treat high blood pressure, ADHD, anxiety/panic disorder, and certain pain conditions. It is classified as a centrally acting α₂ adrenergic agonist. An alternative hypothesis that has been proposed is that clonidine acts centrally as an imidazoline receptor agonist.

Clonidine's effect on reducing circulating epinephrine by a central mechanism was used in the past as an investigatory test for pheochromocytoma, which is a catecholamine-synthesizing tumor, usually of the adrenal medulla. In a clonidine suppression test plasma catecholamines levels are measured before and 3 hours after a 0.3 mg oral test dose has been given to a patient. A positive test occurs if there is no decrease in plasma levels. Clonidine can be used in the treatment of Tourette syndrome (specifically for tics).