Pancuronium Enflurane

The use of both halothane and pancuronium in patients taking tricyclic antidepressant has been reported as resulting in severe tachydysrhythmias. Experiments in dogs have shown that this combination can produce ventricular fibrillation and cardiac arrest (192). Enflurane also resulted in tachycardias in dogs given both imipramine and pancuronium acutely, but not when the imipramine was given chronically for 15 days beforehand. Pancuronium should not be used in patients taking tricyclic antidepressants. 

Edwards RP, Miller RD, Roizen MF, Ham J, Way WL, Lake CR, Roderick L. Cardiac responses to imipramine and pancuronium during anesthesia with halothane or enflurane. Anesthesiology 1979 50(5) 421-5. 

Delisle S, Bevan DR. Impaired neostigmine antagonism of pancuronium during enflurane anaesthesia in man. Br J Anaesth 1982 54(4) 441-5. 

Gregoretti SM, Sohn YJ, Sia RL. Heart rate and blood pressure changes after ORG NC45 (vecuronium) and pancuronium during halothane and enflurane anesthesia. Anesthesiology 1982 56(5) 392-5. 

Clinically important, potentially hazardous interactions with acetazolamide, aminoglycosides, anticholinesterases, bambuterol, calcium channel blockers, chloroquine, chlorpromazine, clindamycin, d-pencillamine, ecothiophate iodine, enflurane, furosemide, halothane, hexomethonium, isoflurane, ketamine, lidocaine, lincomycin, lithium salts, magnesium salts, mannitol, MAO inhibitors, organophosphates, pancuronium, phenytoin, polymyxins, procainamide, quinidine, sevoflurane, spectinomycin, tetracyclines... 

Electrolyte imbalance, and diseases that lead to electrolyte imbalance, such as adrenal cortical insufficiency, alter neuromuscular blockade. Depending on the nature of the imbalance, either enhancement or inhibition may be expected. Magnesium sulfate, used in the management of toxemia of pregnancy, enhances the skeletal-muscle-relaxing effects of pancuronium. Antibiotics such as aminoglycosides, tetracyclines, clindamycin, lincomycin, colistin, and sodium colistimethate augment the pancuronium-induced neuromuscular blockade. Anesthetics such as halothane, enflurane, and isoflurane enhance the action of pancuronium, whereas azathioprine will cause a reversal of neuromuscular blockade. 

Interestingly, anticholinesterases, ACH and ion antagonize competitively pancuronium bromide effectively however, its activity is virtually enhanced by general anaesthetics, for instance halothane, ether, enflurane etc. (see Chapter 4). Therefore, the latter substantial potentiation in pharmacological activity is particularly useful to the anaesthetist due to the faet that it is administered invariably as an adjunct to the anaesthetic procedure in order to cause simultaneous relaxation of the skeletal muscle. 

Fc dall RP, diller RD. Neuromuscular effects of enflurane, alone and combined with < -tubocuraiine,pancuronium, and succinylcholine, nm. Amsthesiology i 915) A2,173-8. 

Tricyclic antidepressants may increase the risk of arrhythmias and hypotension during anaesthesia. Tachyarrhythmias have been seen in patients taking imipramine who were given halothane and pancuronium. Some very limited evidence su ests that amitriptyline may increase the likelihood of enflurane-induced seizure activity. A man taking maprotiline and lithium developed a tonic-clonic seizure when given propofol. Tricyclics may cause an increase in the duration of barbiturate anaesthesia and lower doses of barbiturates may be required. 

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