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Published on: April 9, 2019
Dextromethorphan or dextrorphan have a local anesthetic effect on infiltrative cutaneous analgesia in rats
Yu-Wen Chen1, Koung-Shing Chu, Ching-Nan Lin
1Department of Medical Research, Chi-Mei Medical Center, Tainan, Taiwan.
Background:
Dextromethorphan blocks sodium channels, the site of action of local anesthetics. In this study we evaluated whether dextromethorphan has a local anesthetic effect.
Methods:
We administered dextromethorphan and its active metabolite--dextrorphan, and lidocaine subcutaneously to rats and tested them for cutaneous anesthesia. Drug-drug interactions and systemic safety indices (LD50s/ED50s) were also evaluated.
Results:
Dextromethorphan and dextrorphan had a local anesthetic effect after cutaneous infiltration. The ranking of potencies was dextromethorphan > dextrorphan > lidocaine (P < 0.01 for each comparison). A combination of dextromethorphan or dextrorphan with lidocaine produced an additive effect. Dextromethorphan and dextrorphan had 2.4- and 1.9-fold higher system safety indices than did lidocaine.
Conclusion:
Dextromethorphan and dextrorphan were more potent local anesthetics than lidocaine, but with higher systemic safety indices. Coadministration of dextromethorphan or dextrorphan with lidocaine produced an additive effect.
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