Alpha-adrenergic agonist
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 and α2.
Contents
Classes
Although complete selectivity between receptor agonism is rarely achieved, some agents have partial selectivity.
α1 agonists
α1 agonists: stimulates phospholipase C activity. (vasoconstriction and mydriasis; used as vasopressors, nasal decongestants and eye exams). Selected examples are:
α2 agonists
α2 agonists: inhibits adenylyl cyclase activity. (reduce brainstem vasomotor center-mediated CNS activation; used as antihypertensives, sedatives & treatment of opiate and alcohol withdrawal symptoms). Selected examples are:
- Clonidine (mixed alpha2-adrenergic and imidazoline-I1 receptor agonist)
- Guanfacine,[2] (preference for alpha2A-subtype of adrenoceptor)
- Guanabenz (most selective agonist for alpha2-adrenergic as opposed to imidazoline-I1)
- Guanoxabenz (metabolite of guanabenz)
- Guanethidine (peripheral alpha2-receptor agonist)
- Xylazine,[3]
- Methyldopa
- Fadolmidine
Undetermined/unsorted
The following agents are also listed as agonists by MeSH.[4]
- amidephrine
- amitraz
- anisodamine
- apraclonidine
- brimonidine
- cirazoline
- detomidine
- dexmedetomidine
- epinephrine
- ergotamine
- etilefrine
- indanidine
- lofexidine
- medetomidine
- mephentermine
- metaraminol
- methoxamine
- midodrine
- mivazerol
- naphazoline
- norepinephrine
- norfenefrine
- octopamine
- oxymetazoline
- phenylpropanolamine
- rilmenidine
- romifidine
- synephrine
- talipexole
- tizanidine
Clinical significance
Alpha-adrenergic agonists 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.
See also
References
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- ↑ Lua error in package.lua at line 80: module 'Module:Citation/CS1/Suggestions' not found.
- ↑ Sagvolden T (2006). "The alpha-2A adrenoceptor agonist guanfacine improves sustained attention and reduces overactivity and impulsiveness in an animal model of Attention-Deficit/Hyperactivity Disorder (ADHD)". Behav Brain Funct. 2: 41. doi:10.1186/1744-9081-2-41. PMC 1764416 Freely accessible. PMID 17173664.
- ↑ Lua error in package.lua at line 80: module 'Module:Citation/CS1/Suggestions' not found.
- ↑ MeSH list of agents 82000316
