Lamotrigine reduces painful diabetic neuropathy: a randomized, controlled study.

OBJECTIVE To study the efficacy of lamotrigine in relieving the pain associated with diabetic neuropathy. METHODS The authors randomly assigned 59 patients to receive either lamotrigine (titrated from 25 to 400 mg/day) or placebo over a 6-week period. Primary outcome measure was self-recording of pain intensity twice daily with a 0 to 10 numerical pain scale (NPS). Secondary efficacy measures included daily consumption of rescue analgesics, the McGill Pain Questionnaire (MPQ), the Beck Depression Inventory (BDI), the Pain Disability Index (PDI), and global assessment of efficacy and tolerability. RESULTS Twenty-four of 29 patients (83%) receiving lamotrigine and 22 of 30 (73%) patients receiving placebo completed the study. Daily NPS in the lamotrigine-treated group was reduced from 6.4 +/- 0.1 to 4.2 +/- 0.1 and in the control group from 6.5 +/- 0.1 to 5.3 +/- 0.1 (p < 0.001 for lamotrigine doses of 200, 300, and 400 mg). The results of the MPQ, PDI, and BDI remained unchanged in both groups. The global assessment of efficacy favored lamotrigine treatment over placebo, and the adverse events profile was similar in both groups. CONCLUSIONS Lamotrigine is effective and safe in relieving the pain associated with diabetic neuropathy.