Lamotrigine

The exact mechanism of action is unknown. In vitro studies suggest that lamotrigine blocks voltage-sensitive sodium channels, thereby stabilizing neuronal membranes and inhibiting the presynaptic release of neurotransmitters, principally glutamate. Lamotrigine also may directly inhibit high-frequency sustained repetitive firing of sodium-dependent action potentials. 

Lamotrigine is indicated as an adjunct to other anticonvulsant medications in the treatment of partial seizures in adults 16 years of age and older with epilepsy, and in the treatment of generalized seizures of Lennox-Gastaut syndrome in adult and paediatric patients two years of age and older. Lamotrigine is indicated as monotherapy for treatment of partial seizures (in adults 16 years of age and older) following withdrawal of a concomitantly used enzyme-inducing anticonvulsant medication.