Acetylcholinesterase inhibitor

Overview
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.

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

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

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
 * 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

Effects
Some major effects of anticholinesterases:


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