Cholinergic Drugs

Authors: Flaherty, Alice W.; Rost, Natalia S.

Title: Massachusetts General Hospital Handbook of Neurology, The, 2nd Edition

Copyright 2007 Lippincott Williams & Wilkins

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Cholinergic Drugs

A. Location of receptors

Preganglionic sympathetic nervous system (SNS) + parasympathetic nervous system (PSNS), postganglionic PSNS, postganglionic SNS for sweating and vasodilation.

B. Acetylcholinesterase inhibitors

Inhibit acetylcholine breakdown. E.g., neostigmine (does not penetrate CNS well), physostigmine (does).

C. Muscarinic receptors

Postganglionic. Cause small pupils, high heart rate, secretions, bronchospasm, and bladder tone. Agonists include bethanechol, glycopyrrolate. Antagonists include benztropine, trihexyphenidyl, scopolamine, atropine.

D. Nicotinic receptors

Found in preganglionic ANS (where hexamethonium is an antagonist) and at the NMJ (where curare is an antagonist).

• Anticholinergic toxicity mnemonic: Mad as a hatter (delirium). Plugged as a pig (stool and urinary retention). Dry as a bone (dry mouth, anhidrosis). Blind as a bat (blurred vision). Hot as a hare (fever). Fast as a fibrillation (tachycardia).