Dextrorphan for Prolonged Skin Infiltration Anesthesia by Adding Epinephrine in Rats - Pages 38-41

Kuan-Ting Chen1, Jhi-Joung Wang2 and Yu-Wen Chen2,3

1Department of Anesthesiology, Chi Mei Medical Center, Tainan, Taiwan; 2Department of Medical Research, Chi Mei Medical Center, Tainan, Taiwan; 3Department of Physical Therapy, China Medical University, Taichung, Taiwan



Dextrorphan could be a local anesthetic, while adding epinephrine to the local anesthetics prolonged their duration of action. Here we investigated whether epinephrine as adjuvant could prolong the local anesthetic effect of dextrorphan. The cutaneous analgesic effect of the addition of epinephrine (5 μg/mL) to dextrorphan was assessed in rats following the blockade of cutaneous trunci muscle reflex through subcutaneous injection of drugs. We showed that subcutaneous dextrorphan elicited dose-dependent cutaneous analgesia. Co-administration of epinephrine (5 µg/mL) with dextrorphan at 50% effective dose (ED50) or ED95 had a longer duration than dextrorphan (ED50 or ED95) alone, respectively. This study indicated for the first time that the mixtures of epinephrine with dextrorphan increased the duration as an infiltrative anesthetic.

Keywords: Dextrorphan, Epinephrine, Cutaneous trunci muscle reflex, Duration, Infiltrative cutaneous analgesia.