Lamotrigine and the treatment of mania in bipolar disorder

Anticonvulsants, including valproate and carbamazepine, have established ef ficacy in the treatment of mania. The anticonvulsant, lamotrigine, has been reported to have antimanic and antidepressant efficacy, and mood-stabilisi ng effects in case reports and preliminary open trials. The efficacy and to lerability of lamotrigine has been compared with olanzapine and lithium in a randomised, prospective, controlled fashion over a period of 4 weeks' tre atment in a total of 45 hospitalised patients with DSM-IV-defined mania. Si gnificant improvements of a similar magnitude were observed for all treatme nt groups and lamotrigine was well tolerated. Mechanisms of action proposed to explain the antimanic activity of lamotrigine include inhibition of vol tage-sensitive and use-dependent sodium channels, inhibition of glutamate r elease and calcium channel blockade. Platelet studies have indicated supers ensitivity of glutamate receptors and increased intracellular calcium conce ntrations in patients with mania. Further clinical and mechanistic studies of lamotrigine use in mania are warranted. (C) 1999 Elsevier Science B.V. A ll rights reserved.