Antiepileptic with dual mechanism
ATC code: N03AX09 (Lamotrigine)
Brand names
Lamictal, Crisomet, Lamotrix
Stabilizes the inactivated state of voltage-gated sodium channels, reducing repetitive neuronal firing. Also suppresses glutamate release. Compared with carbamazepine and phenytoin, has a favorable cognitive profile – less sedation and no memory impairment. Metabolized by UGT1A4 glucuronidation. Used in focal and generalized epilepsy, and as a mood stabilizer in bipolar disorder with depressive predominance.
First line
First-line for maintenance therapy of bipolar disorder with depressive predominance per CANMAT 2018 and the Spanish SEP 2024. Not effective for mania. Starting dose 25 mg once daily for 2 weeks with slow titration to 200 mg daily – fast titration raises severe cutaneous reaction risk. Effect develops over 6–8 weeks.
Particularly in bipolar disorder with depressive episode predominance.
First line
First-line in focal epilepsy in adults and children over 2 per ILAE 2017 and the Spanish SEN 2024 consensus alongside levetiracetam and lacosamide. Starting dose 25 mg once daily for 2 weeks, titrated to 100–400 mg daily. Particularly suitable in women of reproductive age – lowest teratogenic potential among classic antiepileptics (malformation risk 2.5% vs 6–10% with valproate).
The drug is promoted for these uses outside international guidelines. Each entry below is analyzed against AEMPS, FDA, EMA, Cochrane and major RCTs.
Not recommended
Lamotrigine is an antiepileptic drug. It is prescribed for epilepsy and for maintenance treatment of bipolar I disorder ( 2018 and NG185 guidelines). For everyday mood stabilization, lamotrigine does not work: no clinical studies of such use exist. The main risk is severe skin reactions (Stevens-Johnson syndrome, toxic epidermal necrolysis), especially with rapid dose escalation or combination with valproate ( boxed warning). If lamotrigine was prescribed for mood stabilization, consider seeking a second opinion.
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Boxed warning
FDA boxed warning: severe cutaneous reactions (Stevens–Johnson syndrome, toxic epidermal necrolysis), especially with rapid titration and in the first 2–8 weeks. Any rash warrants immediate discontinuation.
In pregnant epilepsy patients, lamotrigine is a preferred choice – lowest teratogenic potential among classic antiepileptics. In T2 and T3, levels drop 50–80% due to estrogen-induced metabolism – regular monitoring and dose adjustment needed.
Milk concentrations are high (about 30% of maternal plasma). Infant rash and sedation are possible – monitor activity, weight gain, and skin. If problems arise, switch to formula.
Reference information, not a clinical decision. Discuss feeding pauses or changes with your physician or an IBCLC.
Lamotrigine is evaluated for the following indications with varying evidence strength: Focal epilepsy (evidence tier A), Bipolar disorder maintenance (evidence tier A), Mood stabilization (evidence tier F). See the full indication matrix with dosing and citations above on this page.
Common side effects of Lamotrigine (≥ 1 in 100): Rash (most often in the first 8 weeks), Headache, Dizziness, Drowsiness, Diplopia, Nausea. See the Safety section for uncommon and serious reactions.
FDA category C. In pregnant epilepsy patients, lamotrigine is a preferred choice – lowest teratogenic potential among classic antiepileptics. In T2 and T3, levels drop 50–80% due to estrogen-induced metabolism – regular monitoring and dose adjustment needed.
Milk concentrations are high (about 30% of maternal plasma). Infant rash and sedation are possible – monitor activity, weight gain, and skin. If problems arise, switch to formula.
Lamotrigine is contraindicated in: Lamotrigine hypersensitivity; Age under 2 (most indications); Severe hepatic impairment. Full list in the Safety section.
FDA boxed warning: severe cutaneous reactions (Stevens–Johnson syndrome, toxic epidermal necrolysis), especially with rapid titration and in the first 2–8 weeks. Any rash warrants immediate discontinuation.