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The antagonism of curare: the cardiac effects of atropine and neostigmine

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In a series of 82 selected surgical cases, continuous E.K.G. tracings were recorded during the administration of atropine and neostigmine for the reversal of curare-induced neuromuscular blockade. The drugs were administered intravenously and at separate times at the close of tfie surgical operations, during which various anaesthetic agents had been used.

Analysis of the E.K.G. tracings showed that arrhythmias occurred in 19 cases, and that in most instances the type of arrhythmia was not clinically significant. No arrhythmia was observed following the administrai ion of neostigmine, and none following atropine when the injection time for this drug was greater than 5 seconds. It is suggested that cardiac response to atropine may be related almost entirely to the size of the dose that first reaches the heart; large or rapidly injected doses may affect cardiac conduction at other levels in addition to vagal endings.

It is concluded that neostigmine and atropine are safe to use for the reversal of the effects of curare.


Bien que la néostigmine soit efficace pour antagoniser le blocage neuromusculaire produit par le curare, il est arrivé qu’on lui ait attribué ľapparition ďune arythmie cardiaque. C’est pour cette raison que nous avons étudié attentivemernt les changements électrocardiographiques produits par ľadministration intraveineuse de 1.2 mg. ďatropine et de 2.5 mg. de néostigmine chez 82 malades robustes pour antagoniser ľeffet de curare. Toutes les arythmies, à ľexception de quatre cas de bradycardie, sont survenues à la suite de ľinjection intraveineuse ďatropine. Nous avons observé ces arythmies dont une dissociation auriculoventriculaire chez 10 malades, un rythme nodal chez sept malades, et des arythmies ventriculaires chez huit malades. Les troubles ventriculaires sont allés de systoles ectopiques chez quatre malades, de bréves périodes de bigéminisme chez cinq,à un cas de tachycardie multifocale. Toutes les arythmies ont été transitoires et n’ont laissé aucun changement de ľétat clinique du malade. Toutes les arythmies sont apparues aprés ľinjection intraveineuse trés rapide (moins de cinq secondes) ďatropine. Nous en venons à la conclusion que cette façon ďantagoniser les effets du curare est de toute sécurité, à la condition ďinjecter ľatropine lentement.


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Correspondence to Joel D. Gottlieb or Robert B. Sweet.

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Gottlieb, J.D., Sweet, R.B. The antagonism of curare: the cardiac effects of atropine and neostigmine. Can. Anaes. Soc. J. 10, 114–121 (1963). https://doi.org/10.1007/BF03001934

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  • Halothane
  • Atropine
  • Pulse Rate
  • Cyclopropane
  • Anaesthetic Agent