Systemic mexiletine relieves chronic allodynialike symptoms in rats with ischemic spinal cord injury.

We have recently reported a chronic allodynialike symptom in rats after ischemic spinal cord injury. This pain-related behavior is resistant to a number of pharmacologic treatments, including morphine, clonidine, carbamazepine, baclofen, and muscimol. In the present report, we present evidence indicating that systemic mexiletine, a local anesthetic and antiarrhythmic agent, effectively relieves the allodynia-like symptoms at doses of 15 and 30 mg/kg in these rats without inducing major side effects. It is suggested that systemically applied mexiletine may be useful in treating central pain in patients with spinal cord injury.