anticholinesterase

anticholinesterase /an·ti·cho·lin·es·ter·ase/ (-ko″lin-es´ter-ās) cholinesterase inhibitor.

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an·ti·cho·lin·es·ter·ase (nt-kl-nst-rs, -rz, nt-)

n.

A substance that inhibits the activity of cholinesterases, including acetylcholinesterase.

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anticholinesterase

[an′tikol′ənes′tərās]

a drug that inhibits or inactivates the action of acetylcholinesterase. Drugs of this class cause acetylcholine to accumulate at the junctions of various cholinergic nerve fibers and their effector sites or organs, allowing potentially continuous stimulation of cholinergic fibers throughout the central and peripheral nervous systems. Anticholinesterases include physostigmine salicylate, neostigmine, edrophonium, and pyridostigmine. Neostigmine and pyridostigmine are prescribed in the treatment of myasthenia gravis; edrophonium in the diagnosis of myasthenia gravis and the treatment of overdose of curariform drugs. Many agricultural insecticides have been developed from anticholinesterases; these are the highly toxic chemicals called organophosphates. Nerve gases developed as potential chemical warfare agents contain potent, irreversible forms of anticholinesterase.

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anticholinesterase [an″te-, an″ti-ko″lin-es´ter-ās]

an agent that inhibits acetylcholinesterase, the enzyme that breaks down acetylcholine at junctions of cholinergic nerve endings and effector organs or postsynaptic neurons; this permits the accumulation of acetylcholine and increases the stimulation of cholinergic receptors in the central and peripheral nervous systems. Called also cholinesterase inhibitor.

Organophosphate insecticides and chemical-warfare agents (nerve gases) are highly toxic “irreversible” anticholinesterases; “reversible” anticholinesterases such as neostigmine and physostigmine are used for treatment of myasthenia gravis, glaucoma, and smooth muscle atony of the gastrointestinal tract and for termination of the effect of nondepolarizing neuromuscular blocking agents and cholinergic blocking agents. Poisoning by anticholinesterases is treated with atropine and the cholinesterase reactivator pralidoxime.

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anticholinesterase (an´tīkō´lines´-trās),

n a drug or chemical that inhibits or inactivates the enzyme cholinesterase, resulting in the actions produced by the accumulation of acetylcholine at cholinergic sites.

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anticholinesterase

a drug that inhibits the enzyme acetylcholinesterase, thereby potentiating the action of acetylcholine at postsynaptic membrane receptors in the parasympathetic nervous system.

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anticholinesterase

Pharmacology An agent–eg, certain nerve gases, which blocks nerve impulses by inhibiting anticholinesterase Examples Insecticides–eg, parathion, and nerve gas agents–eg, sarin, soman, tabun; AChEs can be reversible or irreversible Action Eyes–hyperemia and pupillary constriction, GI tract—↑ GI contractions and secretion of gastric acid