Preclinical study in a postoperative pain model to investigate the action of ketamine, lidocaine, and ascorbic acid in reversing fentanyl-induced, non–glutamate-dependent hyperalgesia

Abstract

Fentanyl induced a hyperalgesic effect and was not inhibited by ketamine, lidocaine, and ascorbic acid in rats. Observations show that large doses of opioids may increase postoperative pain.