Anaesthetics neuromuscular blocking

Toxicity is found to be low and related only to the neuromuscular blocking effects. Provided that artificial ventilation is available. 10,000 times the normal effective dose evinces no acute toxicity in anaesthetized cats for up to two hours after injection.asusual. species vary in susceptibility to toxic effects. As might be expected of a higlily-charged cation, absorption from the gut is poor. No hormonal effects have been detected. 

Reilly CS, Nimmo WS (1987) New intravenous anaesthetics and neuromuscular blocking drugs. Drugs 34 98-135 Volwiler EH, Tabem DL (1930) J Am Chem Soc 52 1676... 

Diuretics hypokalaemia, if present, will potentiate neuromuscular blocking agents and perhaps general anaesthetics. 

Meindewar IC, Marshall RJ. Interactions between the neuromuscular blocking drug Org NC 45 and some anaesthetic, analgesic and antimicrobial agents. Br J Anaesth 1981 53(8) 785-92. 

Wierda JM, Kleef UW, Lambalk LM, Kloppenburg WD, Agoston S. The pharmacodynamics and pharmacokinetics of Org 9426, a new non-depolarizing neuromuscular blocking agent, in patients anaesthetized with nitrous oxide, halothane and fentanyl. Can J Anaesth 1991 38(4 Pt l) 430-5. 

Zaagsma, J. Symposium Anaesthetic and neuromuscular blocking drugs . Chem. Wkbl. <55, 5 (1972). 

Encapsulation of neuromuscular blockers by an exogenous host molecule such as CyD would promote dissociation of neuromuscular blockers from their site of action, and result in the reversal of neuromuscular blockage. Negatively charged CyD 37, which has a high affinity for rocuronium 38, a steroidal muscle relaxant, reversed the neuromuscular blocking effect of rocuronium bromide in vitro (mouse hemi-diaphragm) and in vivo (anaesthetized monkeys) [155, 156). 

The neuromuscular blockade due to suxamethonium (succinyl-choline) can be increased and prolonged by lidocaine, procaine and possibly procainamide. These local anaesthetics all have some neuromuscular blocking activity and may theoretically also enhance the block produced by competitive neuromuscular blockers. Increased toxicity occurred when mivacurium and prilocaine were given together for regional anaesthesia. 

Lidocaine, procaine and procainamide all have some neuromuscular blocking activity and may also enhance the block produced by competitive neuromuscular blockers if given in sufficient doses. However, again, there seems to be an absence of reports of this, probably because the amount of local anaesthetic absorbed into the circulation following a local block is usually modest. ... 

A randomised, placebo-controlled, double-blind study in 30 patients found that 150 micrograms/kg of intravenous metoclopramide given prior to anaesthetic induction about 10 minutes before mivacurium 150 micrograms/kg prolonged the duration of action of mivacurium by about 30%.Another report found that infusion rates of mivacurium were reduced by up to about 80% in patients given metoclopramide 10 or 20 mg intravenously, 5 minutes before induction, and metoclopramide delayed complete recovery from neuromuscular block after mivacurium by 36% (10 mg dose) and 50% (20 mg dose). Delays in recovery from mivacurium block of 78% after metoclopramide 20 mg were found in another study. ... 

The interaction between metoclopramide and suxamethonium is an established but not extensively documented interaction of only moderate or minor clinical importance. However anaesthetists should be aware that some enhancement of blockade can occur. The interaction between metoelopra-mide and mivacurium has only more recently been demonstrated. Metoclopramide appears to allow a reduction in the infusion rate of mivaeurium and it causes a significant delay in recovery from neuromuscular block. Care is recommended during combined use. The authors of the suxamethonium reports also point out that plasma cholinesterase activity is reduced in pregnancy and so suxamethonium sensitivity is more likely in obstetric patients. Ester-type local anaesthetics also depend on plasma... 

In onoesdiesie premedication, atropine, and hyoscine block the vagus and reduce mucosal secretions hyoscine also has useful sedative effects. Glycopyrronium is frequently used during anaesthetic recovery to block the muscarinic effects of neostigmine given to reverse a nondepolarising neuromuscular blockade. 

Inhalation anaesthetics may impair the efficacy of anticholinesterases in reversing neuromuscular blockade. Propofol does not affect the reversal of rocuronium block by neostigmine. Physostigmine pre-treatment increased propofol requirements by 20% in one study. 

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