pISSN 2005-9159
eISSN 2093-0569

Korean J Pain 1996; 9(1): 39-45

Published online June 1, 1996

Copyright © The Korean Pain Society.

Effects of Dextromethorphan on the Development of Tachyphylaxis to Sciatic Nerve Blockade Induced by 2-Chloroprocaine in the Rat

Myong-Su Park, Kang-Chang Lee, Tai-Yo Kim

Department of Anesthesiology, Pain clinic, School of Medicine, Iksan, Korea

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.


Tachyphylaxis to local anesthetics has shown to be promote longer interanalgesic intervals between injections. Previous study demonstrated thermal hyperalgesia accelerates development of tachyphylaxis to sciatic nerve blockade in rats, while MK-80l prevents development of tachyphylaxis. Dextromethorphan is one of NMDA receptor antagonist similar to MK-80l. A hypothesis that dextromethorphan would prevent the development of tachyphylaxis was tested in this study. A catheter was surgically implanted along the sciatic nerve a in rat. After recovery from surgery, the animal received repeated injections of 3/2-chloroprocaine followed by motor block testing with or without hot-plate testing at 56 degrees C . In other experiments, dextromethorphan was administered by intraperitoneal injection prior to an injection of local anesthetic through #the implanted catheter. Sensory and motor testing was then carried out. Rats injected with 2-chloroprocaine and subjected to hot-plate testing, developed tachyphylaxis to motor and sensory blockade. However, animals pretreated with dextromethorphan did not develop tachyphylaxis over series of three injections. Dextromethorphan seems to prevent development of tachyphylaxis to sciatic nerve blockade in this rat model. Dextromethorphan, one of N-Methyl-D-aspartate receptor antagonist, can be applied to prolong the effect of local anesthetic.

Keywords: Tachyphylaxis, Local anesthetic, Dextromethorphan, NMDA receptor