Lamotrigine is an anticonvulsant medication used to treat epilepsy and bipolar disorder. For epilepsy, this includes focal seizures, tonic-clonic seizures, and seizures in Lennox-Gastaut syndrome. In bipolar disorder, it is used to treat acute episodes of depression, rapid cycling in bipolar type II, and prevent recurrence in bipolar type I. Lamotrigine was first marketed in the United Kingdom in 1991 and approved for use in the United States in 1994. It is on the World Health Organization's List of Essential Medicines, the most effective and safest medicines needed in a health system.

Lamotrigine prescribing information has a warning about life-threatening skin reactions, including Stevens–Johnson syndrome (SJS), DRESS syndrome and toxic epidermal necrolysis (TEN). The manufacturer states that nearly all cases appear in the first two to eight weeks of therapy, or if the medication is suddenly stopped then resumed at the normal dosage.

Lamotrigine is a member of the sodium channel blocking class of antiepileptic drugs. This may suppress the release of glutamate and aspartate, two of the dominant excitatory neurotransmitters in the CNS. It is generally accepted to be a member of the sodium channel blocking class of antiepileptic drugs, but it could have additional actions since it has a broader spectrum of action than other sodium channel antiepileptic drugs such as phenytoin and is effective in the treatment of the depressed phase of bipolar disorder, whereas other sodium channel blocking antiepileptic drugs are not, possibly on account of its sigma receptor activity. In addition, lamotrigine shares few side-effects with other, unrelated anticonvulsants known to inhibit sodium channels, which further emphasises its unique properties.

Formal Chemical Name (IUPAC)
6-(2,3-dichlorophenyl)-1,2,4-triazine-3,5-diamine

References

https://en.wikipedia.org/wiki/Lamotrigine