Toxic dose
A toxic dose has not been identified for lamotrigine. In adults, ingestions of more than 4 g have been associated with life-threatening toxicity, but mild effects and cardiotoxicity can occur at much lower doses.
Drug-naive children who have ingested more than 10 mg/kg of lamotrigine require medical assessment and observation (see Potential toxic doses of some antiepileptic drugs in drug-naive children for potential toxic doses of some antiepileptic drugs in drug-naive children). Small doses of lamotrigine can provoke seizures in drug-naive children.