nicotinic antagonist nicotinic antagonist 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, 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. comparison mechanism antagonist preferred receptor clinical use ganglionic blocking agents hexamethonium ganglion type none mecamylamine ganglion type trimethaphan ganglion type rarely used for blood pressure decrease during surgery nondepolarizing neuromuscular blocking agents atracurium muscle type muscle relaxant in anaesthesia doxacurium muscle type mivacurium muscle type pancuronium muscle type muscle relaxant in anaesthesia tubocurarine muscle type discovered in arrow poison it was the first pheripheral muscle relaxant. rarely used since 1980s. vecuronium muscle type muscle relaxant in anaesthesia depolarizing neuromuscular blocking agents succinylcholine* muscle type centrally acting nicotinic antagonists 18-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.