Welcome to the MedLibrary.org Wikipedia Supplement on Acetylcholinesterase inhibitor -- Please Click to Return to Front Page

An acetylcholinesterase inhibitor or anti-cholinesterase is a chemical that inhibits the cholinesterase enzyme from breaking down acetylcholine, so increasing both the level and duration of action of the neurotransmitter acetylcholine.

Contents 1 Uses 2 Examples 2.1 Reversible inhibitor 2.1.1 Comparison table 2.2 Quasi-irreversible inhibitor 2.3 Natural Compounds (Supplements) 3 Effects 4 See also 5 References 6 External links

Uses

Acetylcholinesterase inhibitors:

• Occur naturally as venoms and poisons
• Are used as weapons in the form of nerve agents
• Are used medicinally:
  • To treat myasthenia gravis. In myasthenia gravis, they are used to increase neuromuscular transmission.
  • To treat Alzheimer's disease
  • As an antidote to anticholinergic poisoning

Examples

Reversible inhibitor

Compounds which function as reversible competitive or noncompetitive inhibitors of cholinesterase are those most likely to have therapeutic uses. These include:

• Organophosphates
  • Metrifonate
• Carbamates
  • Physostigmine
  • Neostigmine
  • Pyridostigmine
  • Ambenonium
  • Demarcarium
  • Rivastigmine
• Phenanthrine derivatives
  • Galantamine
• Piperidines
  • Donepezil, also known as E2020
• Tacrine, also known as tetrahydroaminoacridine (THA')
• Edrophonium
• Phenothiazines

Comparison table

Comparison of reversible acetylcholinesterase inhibitors

Inhibitor	Duration[1]	Main site of action[1]	Clinical use[1]	Adverse effects[1]
Edrophonium	short (10 min.)	neuromuscular junction	diagnosis of myasthenia gravis
Neostigmine	medium (1-2 hrs.)	neuromuscular junction	Reverse neuromuscular block (intravenously) Treat myasthenia gravis (orally)	visceral
Physiostigmine	medium (0.5-5 hrs.)	postganglionic parasympathetic	treat glaucoma (eye drops)
Pyridostigmine	medium (2-3 hrs.)	neuromuscular junction	Treat myasthenia gravis (orally)
Dyflos	long	postganglionic parasympathetic	historically to treat glaucoma (eye drops)	toxic
Ecothiopate	long	postganglionic parasympathetic	treat glaucoma (eye drops)	systemic effects
Parathion	long	none	toxic

Quasi-irreversible inhibitor

Compounds which function as quasi-irreversible inhibitors of cholinesterase are those most likely to have use as chemical weapons or pesticides. These include:

• Organophosphates
  • Echothiophate
  • Diisopropyl fluorophosphate
  • Cyclosarin
  • Dimethoate
  • Sarin
  • Soman
  • Tabun
  • VX
  • VE
  • VG
  • VM
  • Diazinon
  • Malathion
  • Parathion
• Carbamates
  • Aldicarb
  • Bendiocarb
  • Bufencarb
  • Carbaryl
  • Carbendazim
  • Carbetamide
  • Carbofuran
  • Chlorbufam
  • Chloropropham
  • Ethiofencarb
  • Formetanate
  • Methiocarb
  • Methomyl
  • Oxamyl
  • Phenmedipham
  • Pinmicarb
  • Pirimicarb
  • Propamocarb
  • Propham
  • Propoxur

Natural Compounds (Supplements)

• Huperzine A
• Galantamine

Effects

Some major effects of anticholinesterases:

• Actions on the autonomic nervous system, that is parasympathetic nervous system will cause bradycardia, hypotension, hypersecretion, bronchoconstriction, GI tract hypermotility, and decrease intraocular pressure.
• SLUD syndrome.
• Actions on the neuromuscular junction will result in prolonged muscle contraction.

See also

• Pesticide poisoning

References

1. ^ ^{a b c d} Unless else specified n boxes, then ref is:Rang, H. P. (2003). Pharmacology. Edinburgh: Churchill Livingstone. ISBN 0-443-07145-4.  Page 156

External links

• ATSDR Case Studies in Environmental Medicine: Cholinesterase Inhibitors, Including Pesticides and Chemical Warfare Nerve Agents U.S. Department of Health and Human Services
• MeSH Acetylcholinesterase+inhibitors

v • d • e Pharmacology: enzyme inhibition Class Competitive inhibition - Uncompetitive inhibition - Non-competitive inhibition - Suicide inhibition - Mixed inhibition Substrate Oxidoreductase (EC 1): Aromatase inhibitors - Lipoxygenase inhibitor - Monoamine oxidase inhibitors Transferase (EC 2): Integrase inhibitor - Protein kinase inhibitors - Reverse transcriptase inhibitors Hydrolase (EC 3): Acetylcholinesterase inhibitors - Phosphodiesterase inhibitors - Protease inhibitors (ACE inhibitor, Trypsin inhibitor) - Histone deacetylase inhibitor Lyase (EC 4): Carbonic anhydrase inhibitors

v • d • e Anticholinesterases (N06DA, N07AA) Carbamates Ambenonium - Demecarium - Stigmine (Neostigmine, Physostigmine, Pyridostigmine, Rivastigmine) Other Galantamine - Metrifonate - Donepezil - Tacrine - Edrophonium

v • d • e Psychoanaleptics: anti-dementia drugs (N06D) Anticholinesterases Tacrine - Donepezil - Rivastigmine - Galantamine Other NMDA receptor antagonist (Memantine) - Ginkgo biloba

v • d • e Parasympathomimetics (N07A) Anticholinesterases Stigmine (Neostigmine, Pyridostigmine, Distigmine) - Ambenonium Choline esters Carbachol - Bethanechol Other parasympathomimetics Pilocarpine - Choline alfoscerate

Wikipedia content modification information:

• This page was last modified on 28 May 2008, at 21:52.

Wikipedia Authorship and Review

Wikipedia content provided here is not reviewed directly by MedLibrary.org. Wikipedia content is authored by an open community of volunteers and is not produced by or in any way affiliated with MedLibrary.org.

Wikipedia Usage Guidelines

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article on "Acetylcholinesterase inhibitor".

The URL for this specific entry is:

• http://medlibrary.org/medwiki/Acetylcholinesterase_inhibitor

All Wikipedia text is available under the terms of the GNU Free Documentation License. (See Copyrights for details). Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc.