Alcuronium chloride

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.

Alcuronium chloride

Clinical data
Trade names	Alloferin
Other names	Ro 4-3816, diallylnortoxiferine
AHFS/Drugs.com	International Drug Names
ATC code	M03AA01 (WHO)
Pharmacokinetic data
Metabolism	not metabolized
Elimination half-life	2–4 hours
Excretion	70–90% unchanged in urine 1.3 mL/kg/min
Identifiers
IUPAC name 4,4'-Didemethyl-4,4'-di-propenyltoxiferin-1-dichloride
CAS Number	15180-03-7 N
PubChem CID	5311001
IUPHAR/BPS	341
ChemSpider	20118193 Y
UNII	490DW6501Y
ChEBI	CHEBI:31185 Y
CompTox Dashboard (EPA)	DTXSID0045414
ECHA InfoCard	100.035.648
Chemical and physical data
Formula	C44H50N4O2+2
Molar mass	666.910 g·mol−1
3D model (JSmol)	Interactive image
SMILES [Cl-].[Cl-].OC\C=C6\C[N@+]4(CC=C)CC[C@@]58c%11ccccc%11N7\C=C9\[C@H]1C[C@H]2[C@@]%10(CC[N@@+]2(CC=C)C\C1=C\CO)c3ccccc3N(/C=C(/[C@H]6C[C@H]45)[C@H]78)[C@@H]9%10
InChI InChI=1S/C44H50N4O2.2ClH/c1-3-17-47-19-15-43-35-9-5-7-11-37(35)45-26-34-32-24-40-44(16-20-48(40,18-4-2)28-30(32)14-22-50)36-10-6-8-12-38(36)46(42(34)44)25-33(41(43)45)31(23-39(43)47)29(27-47)13-21-49;;/h3-14,25-26,31-32,39-42,49-50H,1-2,15-24,27-28H2;2*1H/q+2;;/p-2/b29-13-,30-14-,33-25-,34-26-;;/t31-,32-,39-,40-,41-,42-,43+,44+,47-,48-;;/m0../s1 Y Key:CPYGBGOXCJJJGC-GKLGUMFISA-L Y
NY (what is this?)  (verify)

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]

Effects

• Cardiovascular system: histamine release and blockage of the sympathetic ganglia including adrenal medulla could cause hypotension
• Respiratory system: apnea due to phrenic blockage but bronchoconstriction can occur from the histamine release
• Central nervous system: no effect on intraocular pressure
• Autonomic ganglion blockade can cause a decrease in gut motility

Special points

• Duration of action prolonged in states of low potassium, calcium and protein, also in states of high magnesium and acidosis.
• Pharmaceutically incompatible with thiopentone
• Infusion can cause fixed dilated pupils

See also

• The International Pharmacopoeia