Alpha-adrenergic agonists are a class of sympathomimetic agents that selectively stimulates alpha adrenergic receptors.

Selected examples are: α2 agonist: inhibits adenylyl cyclase activity, reduces brainstem vasomotor center-mediated CNS activation; used as antihypertensive, sedative & treatment of opiate dependence and alcohol withdrawal symptoms).

[17] Alpha-adrenergic agonists, more specifically the auto receptors of alpha 2 neurons, are used in the treatment of glaucoma by decreasing the production of aqueous fluid by the ciliary bodies of the eye and also by increasing uveoscleral outflow.

Medications such as clonidine and dexmedetomidine target pre-synaptic auto receptors, therefore leading to an overall decrease in norepinephrine which clinically can cause effects such as sedation, analgesia, lowering of blood pressure and bradycardia.

[18] The reduction of the stress response caused by alpha 2 agonists were theorised to be beneficial peri operatively by reducing cardiac complications, however this has shown not to be clinically effective as there was no reduction in cardiac events or mortality but there was an increased incidence of hypotension and bradycardia.