Atracurium besylate

Toxicity

Excessive doses can be expected to produce enhanced pharmacological effects. Overdosage may increase the risk of histamine release and cardiovascular effects, especially hypotension.

Chemical properties

White to yellowish-white powder, slightly hygroscopic

Originator

Tracrium,Burroughs-Wellcome,US,1983

The Uses of Atracurium besylate

A neuromuscular blocking agent

Indications

For use, as an adjunct to general anesthesia, to facilitate endotracheal intubation and to provide skeletal muscle relaxation during surgery or mechanical ventilation.

What are the applications of Application

Atracurium Besylate is a neuromuscular blocking agent

Background

A non-depolarizing neuromuscular blocking agent with short duration of action. Its lack of significant cardiovascular effects and its lack of dependence on good kidney function for elimination provide clinical advantage over alternate non-depolarizing neuromuscular blocking agents.

Definition

ChEBI: The bisbenzenesulfonate salt of atracurium.

Manufacturing Process

Acryloyl chloride (0.2 mol) in dry benzene (60 ml) was added over 0.5 hour with mechanical stirring to pentane-1,5-diol (0.1 mol), triethylamine (0.2 mol) and pyrogallol (0.1 g) in dry benzene (100 ml). Further dry benzene (ca 100 ml) was added followed by triethylamine (10 ml), and the mixture stirred at 50°C for 0.5 hour. The triethylamine hydrochloride was filtered off and the solvent removed in vacuum to leave a yellow oil which was distilled in the presence of a trace of p-methoxyphenol, excluding light, to give 1,5- pentamethylenediacrylate (12.9 g, 61%, BP 90° to 95°C/0.01 mm Hg).
A solution of tetrahydropapaverine (4.43 g) and 1,5-pentamethylene diacrylate (1.30 g) in dry benzene (15 ml) was stirred under reflux for 48 hours excluding light. The solvent was removed in vacuum and the residual pale red oil dissolved in chloroform (10 ml). Addition of ether (ca 400 ml), followed by saturated ethereal oxalic acid solution (ca 500 ml) gave a flocculent white precipitate, which was filtered off, washed with ether and dried. Crystallization (twice) from ethanol gave N,N'-4,10-dioxa-3,11- dioxotridecylene-1,13-bis-tetrahydropapaverine dioxalate as a white powder (3.5 g, 51%, MP 117° to 121°C).
The free base, N,N'-14,10-dioxa-3,11-dioxotridecylene-1,13-bistetrahydropapaverine, was obtained by basifying an aqueous solution of the dioxalate with sodium bicarbonate solution, followed by extraction with toluene and evaporation of the solvent, to give a colorless viscous oil. Scrupulously dried base (0.5 g) in spectroscopically pure acetonitrile (8 ml) was treated with methyl benzene sulfonate at room temperature for 22 hours. The filtered reaction mixture was added dropwise to mechanically stirred, filtered, dry ether (ca 450 ml). The flocculent white precipitate was filtered off, washed with dry ether, and dried in vacuum over P2O5 at 50°C to yield the product, an off-white powder melting at 85° to 90°C.
In practice it is usually used as dibenzenesulfonate.

brand name

Tracrium (Hospira).

Therapeutic Function

Neuromuscular blocker

Biological Functions

Atracurium besylate (Tracrium) is a benzylisoquinolinium compound like d-tubocurarine. Its actions are similar to those of d-tubocurarine, but its duration of action is shorter (45 minutes) because of spontaneous degradation of the molecule (Hofmann elimination). Because of this, atracurium is useful in patients with low or atypical plasma cholinesterase and in patients with renal or hepatic impairment.

General Description

Atracurium besylate, 2-(2-carboxyethyl)-1,2,3,4-tetrahydro-6,7-dimethoxy-2-methyl-1-veratrylisoquinolinium benzenesulfonate pentamethyleneester (Tracrium), is a nondepolarizing neuromuscular blockingagent that is approximately 2.5 times more potent thand-tubocurarine. Its duration of action (half-life, 0.33 hours)is much shorter than that of d-tubocurarine.

Biochem/physiol Actions

Nicotinic acetylcholine receptor antagonist.

Pharmacokinetics

Atracurium is a nondepolarizing skeletal muscle relaxant. Atracurium can be used most advantageously if muscle twitch response to peripheral nerve stimulation is monitored to assess degree of muscle relaxation. The duration of neuromuscular block produced by Atracurium is approximately one third to one half the duration of block by d-tubocurarine, metocurine, and pancuronium at initially equipotent doses. As with other nondepolarizing neuromuscular blockers, the time to onset of paralysis decreases and the duration of maximum effect increases with increasing doses of Atracurium. Repeated administration of maintenance doses of Atracurium has no cumulative effect on the duration of neuromuscular block if recovery is allowed to begin prior to repeat dosing. Moreover, the time needed to recover from repeat doses does not change with additional doses. Repeat doses can therefore be administered at relatively regular intervals with predictable results.

Clinical Use

Atracurium Besylate is metabolized rapidly and nonenzymatically to yield laudanosineand a smaller quaternary compound ,which do not have neuromuscular blocking activity. In vitroexperiments show that atracurium besylate breaks down atpH 7.4 and 37°C by a Hoffman elimination reaction.Atracurium besylate undergoes enzymatic decompositionof its ester function to yield an inactive quaternary alcoholand quaternary acid. AChE inhibitors such as neostigmine,edrophonium, and pyridostigmine antagonize paralysis byatracurium besylate.

Veterinary Drugs and Treatments

Atracurium is indicated as an adjunct to general anesthesia to produce muscle relaxation during surgical procedures or mechanical ventilation and also to facilitate endotracheal intubation. Atracurium can be used in patients with significant renal or hepatic disease.

Drug interactions

Potentially hazardous interactions with other drugs
Anaesthetics: effects enhanced by ketamine; enhanced effect with volatile liquid general anaesthetics.
Anti-arrhythmics: procainamide enhances muscle relaxant effect.
Antibacterials: aminoglycosides, clindamycin, polymyxin and piperacillin enhance effect of atracurium.
Antiepileptics: muscle relaxant effects antagonised by carbamazepine; effects reduced by long-term use of phenytoin but might be increased by acute use.
Atracurium enhances the neuromuscular block produced by botulinum toxin (risk of toxicity)

Metabolism

Not Available

Metabolism

Atracurium besilate undergoes spontaneous degradation via Hofmann elimination (a non-enzymatic breakdown process occurring at physiological pH and temperature) to produce laudanosine and other metabolites. There is also ester hydrolysis by non-specific plasma esterases. The metabolites have no neuromuscular blocking activity. Excretion of atracurium is in urine and bile, mostly as metabolites.