Canadian Journal of Anesthesia, Vol 10, 114-121, Copyright © 1963 by Canadian Anesthesiologists' Society

The Antagonism of Curare: The Cardiac Effects of Atropine and Neostigmine

¹ Department of Anesthesiology, The University of Michigan Medical School, Ann Arbor, Michigan, U.S.A.

In a series of 82 selected surgical cases, continuous E.K.G. tracings were recorded during the administration of atropine ani neostigmine for the reversal of curare-induced neuromuscular blockade. The drugs were administered intravenously and at separate times at the close of the 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 arrhythmi was not clinically significant. No arrhythmia was observed following the administration 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.