Alcuronium chloride (formerly marketed as Alloferin) is a
neuromuscular blocking (NMB) agent, alternatively referred to as a skeletal
muscle relaxant. It is a semi-synthetic substance prepared from C-
toxiferine I,[1] a bis-quaternary alkaloid obtained from Strychnos toxifera. C-
toxiferine I itself has been tested for its pharmacological action and noted to be a very long acting neuromuscular blocking agent[2] For a formal definition of the durations of actions associated with NMB agents, see page for
gantacurium. The replacement of both the N-methyl groups with N-allyl moieties yielded N,N-diallyl-bis-nortoxiferine, now recognized as alcuronium.
Inclusion of the allylic functions presented an enhanced potential area of biotransformation, and thus alcuronium is observed to have a much shorter duration of neuromuscular blocking action than its parent C-toxiferine I.[3] It also has a more rapid onset of action, and is ~1.5 times as potent as
tubocurarine.[4] The pharmacological action of alcuronium is readily reversed by
neostigmine, and it produces little
histamine release.[5] The major disadvantage of alcuronium is that it elicits a vagolytic effect produced by a selective
atropine-like blockade of cardiac
muscarinic receptors.[4][6][7]
Zahn K, Eckstein N, Tränkle C, Sadée W, Mohr K (2002). "Allosteric modulation of muscarinic receptor signaling: alcuronium-induced conversion of pilocarpine from an agonist into an antagonist". J Pharmacol Exp Ther. 301 (2): 720–8.
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10.1124/jpet.301.2.720.
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Maass A, Mohr K (1996). "Opposite effects of alcuronium on agonist and on antagonist binding to muscarinic receptors". Eur J Pharmacol. 305 (1–3): 231–4.
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10.1016/0014-2999(96)00240-3.
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Jakubík J, Tucek S (1994). "Protection by alcuronium of muscarinic receptors against chemical inactivation and location of the allosteric binding site for alcuronium". J Neurochem. 63 (5): 1932–40.
doi:
10.1046/j.1471-4159.1994.63051932.x.
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Proska J, Tucek S (1994). "Mechanisms of steric and cooperative actions of alcuronium on cardiac muscarinic acetylcholine receptors". Mol Pharmacol. 45 (4): 709–17.
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