Effect of mexiletine on dynamic allodynia induced by chronic constriction injury of the sciatic nerve in rats.

Static and dynamic allodynia occurred in a rat model of neuropathic pain induced by chronic constriction injury (CCI) of the sciatic nerve. Static allodynia was detected within 1 day after the CCI surgery, and persisted for 28 days. Dynamic allodynia displayed a slower course of development with a late onset, and statistically significant changes were achieved between 14 and 28 days after the surgery. Mexiletine at 10 and 30 mg/kg, s.c. produced a significant and dose-dependent inhibition of CCI-induced static and dynamic allodynia on day 14 post-surgery. Pregabalin, used as a reference drug, also significantly inhibited both static and dynamic allodynia at 30 and 60 mg/kg, p.o. These findings rationalize the clinical use of mexiletine for treatment of neuropathic pain.