• Yu-Wen Chen, Koung-Shing Chu, Ching-Nan Lin, Jann-Inn Tzeng, Chin-Chen Chu, Mao-Tsun Lin, and Jhi-Joung Wang.
• Department of Medical Research, Chi-Mei Medical Center, Tainan, Taiwan.
• Anesth. Analg. 2007 May 1; 104 (5): 1251-5, tables of contents.

BackgroundDextromethorphan blocks sodium channels, the site of action of local anesthetics. In this study we evaluated whether dextromethorphan has a local anesthetic effect.MethodsWe 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.ResultsDextromethorphan 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.ConclusionDextromethorphan 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.

23 keywords...

hide…