A nicotinic antagonist is a type of anticholinergic drug that inhibits the action of acetylcholine (ACh) at nicotinic acetylcholine receptors. These compounds are mainly used for peripheral muscle paralysis in surgery, the classical agent of this type being tubocurarine,P. Taylor (1990). In Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th Ed., (A. G. Gilman et al., Eds.), pp. 166-186, New York: Pergamon Press. but some centrally acting compounds such as bupropion, mecamylamine, and 18-methoxycoronaridine block nicotinic acetylcholine receptors in the brain and have been proposed for treating nicotine addiction.

+ComparisonMechanismAntagonistPreferred receptorClinical useGanglionic blocking agentsHexamethonium Ganglion type None Page 149Mecamylamine Ganglion typeTrimethaphan Ganglion type Rarely used for blood pressure decrease during surgery Nondepolarizing neuromuscular blocking agentsAtracurium Muscle type Muscle relaxant in anaesthesiaDoxacurium Muscle typeMivacurium Muscle typePancuronium Muscle type Muscle relaxant in anaesthesiaTubocurarine Muscle type Discovered in arrow poison; it was the first peripheral muscle relaxant. Rarely used since the 1980s.Vecuronium Muscle type Muscle relaxant in anaesthesia Depolarizing neuromuscular blocking agentsSuccinylcholine* Muscle type Centrally acting nicotinic antagonists18-Methoxycoronaridine α3β4 Bupropion α3β4. α4β2, α1β1γδ Antidepressant (NDRI) Hydroxybupropion α3β4. α4β2, α1β1γδ Antidepressant (NDRI). Metabolite of bupropion. Threohydrobupropion α3β4. Antidepressant (NDRI). Metabolite of bupropion. Dextromethorphan α3β4. α4β2, α7 Common over the counter antitussive. Dextrorphan α3β4. α4β2, α7 Metabolite of dextromethorphan; no accepted medical uses.3-Methoxymorphinan α3β4 Secondary metabolite of dextromethorphan; not used in medical practice. Unknown medical efficacy.

Note: Succinylcholine is a nicotinic agonist. See neuromuscular blocking agents page for details on the mechanism of action.

See also Nicotinic acetylcholine receptor Nicotinic agonist Muscarinic acetylcholine receptor Muscarinic agonist Muscarinic antagonist

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