adrenergic agonist

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Related to adrenergic agonist: Adrenergic antagonist

adrenergic agonist

A family of agents which have adrenaline-like effects, acting directly or indirectly on any of the five G-protein-coupled adrenergic receptors: apha1, alpha2, beta1, beta2, beta3.

Actions of adrenergic agonists
alpha1 receptors: Activate phospholipase C (via Gq), increasing protein kinase C activity.
alpha2: receptors Inhibit adenylate cyclase (via G1), decreasing protein kinase A activity.
beta receptors: Activate adenylate cyclase (via Gs), increasing protein kinase A activity.

adrenergic agonist

Any of a group of therapeutic agents, e.g. epinephrine, that mimic or stimulate the sympathetic nervous system.
See also: agonist

sympathomimetic drugs 

Drugs that produce an effect similar to that obtained by stimulation of the sympathetic nervous system. Some of these predominantly act on the adrenergic alpha-receptors (e.g. noradrenaline (norepinephrine)), while others act on the adrenergic beta-receptors (e.g. isoproterenol). Others have little direct effect on the adrenergic receptors but enhance the release of natural catecholamine from the sympathetic nerve terminals (e.g. amphetamine, phenylpropanolamine). Sympathomimetic drugs are used (1) in the treatment of open-angle glaucoma by decreasing aqueous humour secretion and increase the outflow through the trabecular meshwork thus reducing the intraocular pressure (e.g. adrenaline (epinephrine), apraclonidine, dipivefrine hydrochloride, brimonidine tartrate), (2) dilate the pupil without affecting accommodation (e.g. phenylephrine) and (3) constrict conjunctival blood vessels (e.g. naphazoline, tetrahydrozoline). Syn. adrenergic agonist; adrenergic stimulating agent. See alpha-adrenergic agonist; mydriatic.

ad·re·ner·gic ag·o·nist

(adrĕ-nĕrjik agŏ-nist)
An agent capable of combining with receptors to initiate actions of or like epinephrine.
See: agonist
See also: epinephrine
References in periodicals archive ?
In 2003, a meta-analysis of 23 clinical trials comprising 3,395 patients concluded that the use of alpha-2 adrenergic agonists reduced mortality and myocardial infarction during and after cardiovascular surgery; additionally, lower rates of ischemia were also found, probably accounting for lower mortality rates (39).
Animal studies support the concept that in humans prenatal exposure to continuous high doses of beta 2 adrenergic agonists can permanently dysregulate signaling from the beta 2 adrenergic receptor.
Pirbuterol (Maxair Autohaler[R]) is a short-acting selective beta-2 adrenergic agonist.
The complimentary action of local anaesthetics and [alpha]-2 adrenergic agonists accounts for their profound analgesic properties.
Alpha-2 adrenergic agonists are being evaluated extensively as an alternative to neuraxial opioids, as an adjuvant.
1,2) Dexmedetomidine, a highly selective [alpha]2 adrenergic agonist, as an adjuvant to hyperbaric bupivacaine in spinal anaesthesia provides good quality of intraoperative and prolonged post-operative analgesia with minimal side effects.
Hence [alpha]2 adrenergic agonist, Clonidine is being used as an alternative drug for postoperative analgesia which is free of some opioids related but not all side effects.
The local anesthetics act by blocking sodium channels, whereas the alpha 2 adrenergic agonist acts by binding to pre synaptic C fibre and post synaptic dorsal horn neurons.