Abstract

Clonidine (Dixarit) is a synthetic imidazoline first introduced under the brand name Catapres for the treatment of hypertension. The mechanism of the drug’s hypotensive action is not understood. In cats prolonged administration makes blood vessels less capable of responding to, or sustaining, the vasoconstrictor and vasodilator effects of noradrenaline and isoprenaline.¹ These experimental observations suggested that clonidine might be useful in the prophylactic management of migraine.