Parasympathomimetic drug


Parasympathomimetic drug

A parasympathomimetic drug is a drug or poison that acts by stimulating or "mimicking" the parasympathetic nervous system (PSNS).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=] These chemicals are also called cholinergics because acetylcholine (ACh) is the neurotransmitter used by the PSNS. Chemicals in this family can act either directly by stimulating the nicotinic or muscarinic receptors, or indirectly by inhibiting cholinesterase, promoting acetylcholine release, or other mechanisms. [Brenner, G. M. (2000). "Pharmacology." Philadelphia, PA: W.B. Saunders Company. ISBN 0-7216-7757-6]

Some chemical weapons such as sarin or VX, non-lethal riot control agents such as tear gas, and insecticides such as diazinon fall into this category.

Pharmaceuticals

Direct-acting

These act by stimulating the nicotinic or 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-adrenergics. 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-adrenergics
**clonidine (α-receptor agonist, α2 > α1, giving negative feedback)
**propranolol (β2 antagonist)
**atenolol (β1 antagonist)
**prazosin (α1 antagonist)
**methyldopa (α2 agonist giving negative feedback)

References

ee also

* Sympathomimetic drug

External links

*


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Look at other dictionaries:

  • parasympathomimetic — 1. adjective Acting by stimulating the parasympathetic nervous system. 2. noun A parasympathomimetic drug …   Wiktionary

  • parasympathomimetic — [par΄əsim΄pə thō΄mi met′ik] adj. 〚/span> PARASYMPATHETIC + MIMETIC〛 having an effect similar to that produced when the parasympathetic nervous system is stimulated: said of drugs, chemicals, etc. * * * par·a·sym·pa·tho·mi·met·ic (pă r əsĭm pə thō …   Universalium

  • parasympathomimetic — Relating to drugs or chemicals having an action resembling that caused by stimulation of the parasympathetic nervous system. SEE ALSO: cholinomimetic. [para + G. sympatheia, sympathy, + mimetikos, imitative] * * * para·sym·pa·tho·mi·met·ic .par ə …   Medical dictionary

  • parasympathomimetic — n. a drug that has the effect of stimulating the parasympathetic nervous system. The actions of parasympathomimetic drugs are cholinergic (resembling those of acetylcholine) and include stimulation of skeletal muscle, vasodilatation, depression… …   The new mediacal dictionary

  • Cholinergic — The N,N,N trimethylethanolammonium cation, with an undefined counteranion, X− …   Wikipedia

  • carbachol — A parasympathetic stimulant used locally in the eye for the treatment of glaucoma. * * * car·ba·chol kär bə .kȯl, .kōl n a synthetic parasympathomimetic drug C6H15ClN2O2 that is used in veterinary medicine and topically to treat glaucoma * * * n …   Medical dictionary

  • Nicotinic agonist — A nicotinic agonist is a drug which enhances the action at the nicotinic acetylcholine receptor (nAChR). Examples include: nicotine (by definition the nicotinic acetylcholine receptor is named for its affinity for nicotine) acetylcholine, the… …   Wikipedia

  • pilocarpine — An alkaloid obtained from the leaves of Pilocarpus; Microphyllus or P. jaborandi (family Rutaceae), shrubs of the West Indies and tropical America; a parasympathomimetic agent used as a diaphoretic, sialogogue, and stimulant of intestinal… …   Medical dictionary

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