Lamotrigine for central poststroke pain - A randomized controlled trial

Objective: Central poststroke pain (CPSP) is usually difficult to treat. Am itriptyline, the only oral preparation shown to be effective in a randomize d controlled trial, is often associated with a range of side effects relate d to the many mechanisms of actions of tricyclic antidepressants. We invest igated the effect of lamotrigine, a drug that reduces neuronal hyperexcitab ility, on poststroke pain. Methods: Thirty consecutive patients with CPSP ( median age 59 years, range 37 to 77; median pain duration 2.0 years, range 0.3 to 12) from two centers participated in a randomized, double-blind, pla cebo-controlled cross-over study. The study consisted of two 8-week treatme nt periods separated by 2 weeks of wash-out. The primary endpoint was the m edian value of the mean daily pain score during the last week of treatment while treated with 200 mg/d lamotrigine. Secondary endpoints were median pa in scores while on lamotrigine 25 mg/d, 50 mg/d, and 100 mg/d; a global pai n score; assessment of evoked pain; areas of spontaneous pain; and allodyni a/ dysesthesia. Results: Lamotrigine 200 mg/d reduced the median pain score to 5, compared to 7 during placebo (p = 0.01) in the intent-to-treat popul ation of 27 patients. No significant effect was obtained at lower doses. Tw elve patients (44%) responded to the treatment. There was a uniform tendenc y to reduction of all secondary outcome measures, but lamotrigine only had significant effects on some of the secondary outcome measures. Lamotrigine was well tolerated with few and transient side effects. Two mild rashes occ urred during lamotrigine treatment, one causing withdrawal from study. Conc lusions: Oral lamotrigine 200 mg daily is a well tolerated and moderately e ffective treatment for central poststroke pain. Lamotrigine may be an alter native to tricyclic antidepressants in the treatment of CPSP.