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.

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.

[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.