An adrenergic alpha-agonist
(or alpha-adrenergic agonist
) is a drug that selectively stimulates alpha adrenergic receptors
. The alpha-adrenergic receptor has two subclasses α1
Although complete selectivity between receptor agonism is rarely achieved, some agents have partial selectivity.
α1 agonists: stimulates phospholipase C activity. (vasoconstriction and mydriasis; used as vasopressors, nasal decongestants and eye exams). Selected examples are:
agonists: inhibits adenylyl cyclase activity. (reduce brainstem vasomotor center-mediated SNS activation; used as antihypertensives, sedatives & treatment of opiate and alcohol withdrawal
symptoms). Selected examples are:
The following agents are also listed as agonists by MeSH
Alpha-adrenergic agonists are used in the treatment of glaucoma
by decreasing the production of aqueous fluid by the ciliary bodies of the eye.