la-MOE-tri-jeen 
Absorption: 98% absorbed following oral administration.
Distribution: Enters breast milk. Highly bound to melanin-containing tissues (eyes, pigmented skin).
Metabolism/Excretion: Mostly metabolized by the liver via glucuronidation to inactive metabolites; 10% excreted unchanged by the kidneys.
Half-life: Children taking enzyme–inducing anticonvulsants: 7–10 hr; Children taking enzyme inducers and valproic acid: 15–27 hr; Children taking valproic acid: 44–94 hr; Adults: 25.4 hr (during chronic therapy of lamotrigine alone).
Contraindicated in:
Use Cautiously in:
CV: CARDIAC ARREST, arrhythmias, bradycardia, heart block, QRS interval prolongation.
Derm: DRUG REACTION WITH EOSINOPHILIA AND SYSTEMIC SYMPTOMS (DRESS), STEVENS-JOHNSON SYNDROME, photosensitivity, rash (higher incidence in children, patients taking valproic acid, high initial doses, or rapid dose increases).
EENT: blurred vision, double vision, rhinitis.
GI: HEPATIC FAILURE, nausea, vomiting.
GU: vaginitis.
Hemat: HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS.
MS: arthralgia.
Neuro: ASEPTIC MENINGITIS, SUICIDAL THOUGHTS, ataxia, dizziness, headache, behavior changes, depression, drowsiness, insomnia, tremor.
Drug-Drug:
Epilepsy
In Combination with Other Antiepileptic Agents
13 yr; Extended-release tablets): Patients taking anticonvulsant drugs other than carbamazepine, phenobarbital, phenytoin, primidone, or valproate — 25 mg once daily for first 2 wk, then 50 mg once daily for next 2 wk; then 100 mg once daily for 1 wk, then 150 mg once daily for 1 wk, then 200 mg once daily for 1 wk, then ↑ by 100 mg/day every wk to maintenance dose of 300–400 mg once daily; Patients taking carbamazepine, phenobarbital, phenytoin, or primidone (and not valproate) — 50 mg once daily for first 2 wk, then 100 mg once daily for next 2 wk, then 200 mg once daily for 1 wk, then 300 mg once daily for 1 wk, then 400 mg once daily for 1 wk, then ↑ by 100 mg/day every wk to maintenance dose of 400–600 mg once daily; Patients taking regimen containing valproate — 25 mg every other day for first 2 wk, then 25 mg once daily for next 2 wk, then 50 mg once daily for 1 wk, then 100 mg once daily for 1 wk, then 150 mg once daily for 1 wk, then maintenance dose of 200–250 mg once daily.16 yr; Immediate-release, chewable, or orally disintegrating tablets): Patients taking carbamazepine, phenobarbital, phenytoin, or primidone (and not valproate) — After achieving a dose of 500 mg/day (as per dosing guidelines above), ↓ dose of other antiepileptic by 20% weekly over 4 wk; Patients taking regimen containing valproate — After achieving a dose of 200 mg/day (as per dosing guidelines above), ↓ valproate dose by 500 mg/day on a weekly basis until a dose of 500 mg/day is achieved. Maintain the valproate dose of 500 mg/day and the lamotrigine dose of 500 mg/day for 1 wk. Then ↑ lamotrigine dose to 300 mg/day and ↓ valproate dose to 250 mg/day, and maintain these doses for 1 wk. Then discontinue valproate and ↑ lamotrigine dose by 100 mg/day every wk until maintenance dose of 500 mg/day is achieved.13 yr; Extended-release tablets): Patients taking carbamazepine, phenobarbital, phenytoin, or primidone (and not valproate) — After achieving a dose of 500 mg/day (as per dosing guidelines above), ↓ dose of other antiepileptic by 20% weekly over 4 wk. Two wk later, ↓ dose of lamotrigine by 100 mg/day every wk to achieve maintenance dose of 250–300 mg/day; Patients taking regimen containing valproate — After achieving a dose of 150 mg/day (as per dosing guidelines above), ↓ valproate dose by 500 mg/day on a weekly basis until a dose of 500 mg/day is achieved. Maintain the valproate dose of 500 mg/day and the lamotrigine dose of 150 mg/day for 1 wk. Then ↑ lamotrigine dose to 200 mg/day and ↓ valproate dose to 250 mg/day, and maintain these doses for 1 wk. Then discontinue valproate and ↑ lamotrigine dose to 250–300 mg/day; Patients taking anticonvulsant drugs other than carbamazepine, phenobarbital, phenytoin, primidone, or valproate — After achieving a dose of 250–300 mg/day (as per dosing guidelines above), ↓ dose of other antiepileptic by 20% weekly over 4 wk.Bipolar Disorder
Escalation Regimen(Generic available)
NDC Code*