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.
