Oxcarbazepine for treating paroxysmal painful symptoms in multiple sclerosis: a pilot study

Oxcarbazepine (OXC) is an anitepileptic medication recently approved as monotherapy for partial onset seizure and demonstrated to be useful in the treatment of several neuropathic pain. We performed an open-label pilot study of OXC (dosage 600-1200 mg/day) in 12 multiple sclerosis (MS) patients suffering painful paroxysmal symptoms. Eight subjects were female and 4 male, with a mean age of 43.6 years, mean disease duration of 7.3 years and mean score at the EDSS of 3.2. Ten patients had a relapsing-remitting disease course, 1 had secondary progressive and 1 had primary progressive course. Painful paroxysmal symptoms (PPS) were defined as transient painful symptoms in any area of the body, with abrupt onset, brief duration, from a few seconds to a few minutes, with repetitive and stereotyped features. The subjective level of the PPS was scored using a three-point scale (0-3). The mean dosage of OXC was 1033 mg daily. Nine patients experienced a complete and sustained recovery within 1 month from treatment initiation (T0 vs. T1, p>0.05). Two patients dropped out of the study due to adverse effects: 1 case of nausea and dizziness, 1 case of C. hyponatraemia. The medication was well tolerated in the majority of the subjects. The study results provide a new possibility for treating painful symptoms in MS, but efficacy on PPS must be confirmed in a larger study.