Parasympathomimetic drug 740295 225514394 2008-07-14T02:26:24Z Arcadian 104523 ref A '''parasympathomimetic drug''' is a [[medication|drug]] or [[poison]] that acts by stimulating or '''''mimicking''''' the [[parasympathetic nervous system]] (PSNS).<ref name="urlDorlands Medical Dictionary:parasympathomimetic">{{cite web |url=http://www.mercksource.com/pp/us/cns/cns_hl_dorlands_split.jsp?pg=/ppdocs/us/common/dorlands/dorland/six/000078652.htm |title=Dorlands Medical Dictionary:parasympathomimetic |format= |work= |accessdate=}}</ref> These chemicals are also called [[cholinergic]]s because [[acetylcholine]] (ACh) is the [[neurotransmitter]] used by the PSNS. Chemicals in this family can act either directly by stimulating the [[nicotinic acetylcholine receptor|nicotinic]] or [[muscarinic acetylcholine receptor|muscarinic]] receptors, or indirectly by inhibiting [[cholinesterase]], promoting acetylcholine release, or other mechanisms. <ref>Brenner, G. M. (2000). ''Pharmacology.'' Philadelphia, PA: W.B. Saunders Company. ISBN 0-7216-7757-6</ref> Some [[chemical weapons]] such as [[sarin]] or [[VX (nerve agent)|VX]], non-lethal [[riot control agent]]s such as [[CS gas|tear gas]], and insecticides such as [[diazinon]] fall into this category. ==Pharmaceuticals== ===Direct-acting=== These act by stimulating the [[nicotinic acetylcholine receptor|nicotinic]] or [[muscarinic acetylcholine receptor|muscarinic]] receptors. *'''Choline esters''' **[[Acetylcholine]] (all [[acetylcholine receptors]]) **[[Bethanechol]] ([[M3 receptors]]) **[[Carbachol]] (all [[muscarinic receptors]] and some [[nicotinic receptors]]) **[[Methacholine]] (all [[muscarinic receptors]]) *'''Plant alkaloids''' **[[Nicotine]] **[[Muscarine]] **[[Pilocarpine]] ([[M3 receptors]]) ===Indirect-acting=== Indirect acting parasympathomimetic drugs may be either reversible cholinesterase inhibitors, irreversible cholinesterase inhibitors or drugs that promote ACh release or [[anti-adrenergic]]s. The latter inhibits the antagonistic system, the [[sympathetic nervous system]]. *'''Reversible cholinesterase inhibitors''' **[[Donepezil]] **[[Edrophonium]] **[[Neostigmine]] **[[Physostigmine]] **[[Pyridostigmine]] **[[Rivastigmine]] **[[Tacrine]] *'''Irreversible cholinesterase inhibitors''' **[[Echothiophate]] **[[Isoflurophate]] **[[Malathion]] *'''ACh release promoters''' **[[Cisapride]] **[[Metoclopramide]] *'''[[Anti-adrenergic]]s''' **[[clonidine]] (α-[[adrenergic agonist|receptor agonist]], [[Alpha-2 receptor|α<sub>2</sub>]] > [[alpha-1 receptor|α<sub>1</sub>]], giving [[negative feedback]]) **[[propranolol]] ([[non-selective Beta adrenergic receptor|β2]] antagonist) **[[atenolol]] ([[Beta-1 adrenergic receptor|β1]] antagonist) **[[prazosin]] ([[alpha-1 receptor|α1]] antagonist) **[[methyldopa]] ([[Alpha-2 receptor|α<sub>2</sub>]] agonist giving [[negative feedback]]) ==References== <references/> ==See also== * [[Sympathomimetic drug]] ==External links== * {{MeshName|Parasympathomimetics}} {{pharm-stub}} {{Receptor agonists and antagonists}} {{Parasympathomimetics}} {{Antiglaucoma preparations and miotics}} [[Category:Parasympathomimetics]] [[de:Parasympathomimetikum]] [[es:Parasimpaticomimético]] [[nl:Parasympathicomimeticum]] [[ja:コリン作動薬]] [[pl:Parasympatykomimetyki]] [[sk:Parasympatomimetikum]]