541-22-0

Crystals derived from methanol and acetone.

Water soluble.

ACUTE/CHRONIC HAZARDS: When heated to decomposition this compound emits very toxic fumes.

Flash point data for this chemical are not available. DECAMETHONIUM DIBROMIDE is probably combustible.

Decamethonium is a depolarizing neuromuscular blocking agent. It is a partial agonist of muscle-type nicotinic acetylcholine receptors (nAChRs). Decamethonium activates α1β1-containing adult mouse muscle-type nAChRs expressed in X. laevis oocytes with an EC₅₀ value of 40 μM using voltage clamp electrophysiology. It is also a nondepolarizing antagonist of neuronal-type nAChRs, inhibiting mouse α7-, α3β2-, α3β4-, and α4β2-containing receptors with IC₅₀ values of 7.4, 405, 28, and 59 μM, respectively. Decamethonoium is a competitive antagonist of α4β2-containing nAChRs expressed in SH-EP1 cells (IC₅₀ = 52 μM for the human receptor). It also inhibits electric eel acetylcholinesterase (AChE) and blocks electrically-evoked tibialis muscle twitches in anesthetized cats with ED₉₅ values of 35 and 70 μg/kg for cats under chloralose and ether anesthesia, respectively. Formulations containing decamethonium have been used to induce paralysis during anesthesia.

crystalline solid

antipsychotic

Syncurine (GlaxoSmithKline).

Decamethonium was one of the first neuromuscular blocking agents to be synthesized. An SAR study on a series of bis-quaternary ammonium compounds with varying numbers of methylene groups separating the nitrogen atoms demonstrated that maximal neuromuscular blockade occurred with 10 to 12 unsubstituted methylene groups. Activity diminished as the number of carbons was either decreased or increased. The compound with six methylene groups, hexamethonium, is a nicotinic antagonist at autonomic ganglia (ganglionic blocking agent). All the compounds in this series that possessed neuromuscular blocking activity also caused depolarization of the postjunctional membrane.

[1] W. D. M. PATON  Eleanor J Z. The action of d-tubocurarine and of decamethonium on respiratory and other muscles in the cat[J]. Journal of Physiology-London, 1951, 112 3-4: 311-331. DOI: 10.1113/jphysiol.1951.sp004531
[2] ROGER L PAPKE J A S Lynn Wecker. Activation and inhibition of mouse muscle and neuronal nicotinic acetylcholine receptors expressed in Xenopus oocytes.[J]. Journal of Pharmacology and Experimental Therapeutics, 2010, 333 2: 501-518. DOI: 10.1124/jpet.109.164566
[3] J BREK EATON. Characterization of human alpha 4 beta 2-nicotinic acetylcholine receptors stably and heterologously expressed in native nicotinic receptor-null SH-EP1 human epithelial cells.[J]. Molecular Pharmacology, 2003, 64 6: 1283-1294. DOI: 10.1124/mol.64.6.1283
[4] B ROBAIRE  G K. Effects of edrophonium, eserine, decamethonium, d-tubocurarine, and gallamine on the kinetics of membrane-bound and solubilized eel acetylcholinesterase.[J]. Molecular Pharmacology, 1975, 11 6: 722-734.