Lamotrigine
Pronunciation: pronunciation varies by local usage.
Last medically reviewed: August 14, 2026, by Dr. Roshan Basnet, MBBS, MD (Internal Medicine).
- Generic name
- lamotrigine
- Drug class
- Anticonvulsant and mood stabilizer
- Form
- Tablet (immediate-release)
- Route
- Oral
- Legal status
- Prescription-only
Availability and supply rules vary by country
Trade names by country: United States · Canada
Australia: · Full directory
What lamotrigine is and how it works
Lamotrigine is an anticonvulsant and mood-stabilizing medicine used for epilepsy (as adjunctive therapy and monotherapy in certain patients) and for maintenance treatment of Bipolar I Disorder to delay the occurrence of mood episodes. (1)
It is available as immediate-release tablets. Treatment must be started and titrated slowly to reduce the risk of serious skin rash. Dosing depends on other medications being taken and the condition treated. For Bipolar I Disorder, it is a maintenance treatment intended to delay the time to occurrence of mood episodes.
Mechanism of action: how lamotrigine works
It is classified as an antiepileptic drug (anticonvulsant) and mood stabilizer. (1)
What lamotrigine is used for
Epilepsy adjunctive therapy
Lamotrigine is indicated as adjunctive therapy for partial seizures and Lennox-Gastaut syndrome in patients aged 2 years and older. (1)
Epilepsy monotherapy
Lamotrigine is indicated for conversion to monotherapy in patients aged 16 years and older with partial seizures who are converting from specific other antiepileptic drugs, as described in the full prescribing information. (1)
Bipolar I Disorder maintenance
Lamotrigine is indicated for the maintenance treatment of Bipolar I Disorder to delay the time to occurrence of mood episodes (depression, mania, hypomania, mixed episodes) in adults aged 18 years and older. (1)
Before taking lamotrigine
Do not take / not appropriate for
- (all uses) (1)
- Lamotrigine’s Bipolar I Disorder indication is for maintenance treatment, to delay the time to occurrence of mood episodes (depression, mania, hypomania, mixed episodes). (Bipolar I Disorder) (1)
Tell your clinician about
- All current medicines, especially valproate, carbamazepine, phenytoin, phenobarbital, primidone, rifampin, or estrogen-containing oral contraceptives.
- Pregnancy, plans for pregnancy, or breastfeeding (a pregnancy registry is available at 1-888-233-2334 or 1-800-336-2176).
- Any signs of depression, suicidal thoughts, or unusual mood changes.
How to take lamotrigine
- Take lamotrigine exactly as prescribed by your prescriber, following the dosing schedule they give you. Your dose will be started low and increased slowly according to a schedule to reduce the risk of a serious rash.
- Lamotrigine starter kits may be provided for the first 5 weeks to help follow the recommended titration schedule.
- Do not change the dose or stop taking lamotrigine without your prescriber’s instruction. Abrupt withdrawal can cause seizures; a slow taper over at least 2 weeks is usually required.
- If taking valproate, enzyme-inducing drugs, or oral contraceptives, your lamotrigine dose will be adjusted accordingly.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1)
Missed dose
Contact the prescriber for instructions rather than adjusting the dose yourself.
Overdose
No specific overdose-management protocol for lamotrigine was found in the reviewed source. Seek emergency medical attention if overdose is suspected.
Side effects
Side effects vary by indication. The most common include dizziness, headache, double vision, and nausea. A serious rash is possible; see the serious warnings section.
Dizziness
What to notice: Not established from the sources reviewed: a specific patient-facing symptom description was not established in the sources reviewed for this page beyond the reaction name itself.
What to do: Tell your prescriber about this. (1)
Headache
What to notice: Not established from the sources reviewed: a specific patient-facing symptom description was not established in the sources reviewed for this page beyond the reaction name itself.
What to do: Tell your prescriber about this. (1)
Diplopia (double vision)
What to notice: Not established from the sources reviewed: a specific patient-facing symptom description was not established in the sources reviewed for this page beyond the reaction name itself.
What to do: Report to your prescriber for evaluation. (1)
Ataxia (impaired coordination)
What to notice: Not established from the sources reviewed: a specific patient-facing symptom description was not established in the sources reviewed for this page beyond the reaction name itself.
What to do: Tell your prescriber about this. (1)
Nausea
What to notice: Not established from the sources reviewed: a specific patient-facing symptom description was not established in the sources reviewed for this page beyond the reaction name itself.
What to do: Tell your prescriber about this. (1)
Somnolence (sleepiness)
What to notice: Not established from the sources reviewed: a specific patient-facing symptom description was not established in the sources reviewed for this page beyond the reaction name itself.
What to do: Discuss with your prescriber if affected. (1)
Rash
What to notice: Any new skin rash no matter how mild.
What to do: Seek immediate medical evaluation; lamotrigine may need to be discontinued unless the rash is clearly not drug-related. (1)
Serious rash (including Stevens-Johnson syndrome)
What to notice: The reviewed source describes it only as a life-threatening serious rash, including Stevens-Johnson syndrome and toxic epidermal necrolysis.
What to do: Seek emergency medical attention immediately. Let the emergency clinician evaluate the rash and advise on whether lamotrigine should be continued or stopped. (1)
Hypersensitivity reactions
What to notice: Fever or swollen lymph nodes, which may occur even without a rash.
What to do: Seek immediate medical evaluation. (1)
Suicidal thoughts or behavior
What to notice: Antiepileptic drugs as a class have been associated with an increased risk of suicidal thoughts or behavior, requiring close monitoring, especially early in treatment.
What to do: Contact your prescriber or emergency services immediately. (1)
Blood dyscrasias
What to notice: The reviewed source reports neutropenia, thrombocytopenia, and pancytopenia (types of low blood cell counts) with lamotrigine.
What to do: Contact your prescriber for evaluation. (1)
Multiorgan failure
What to notice: The reviewed source describes multiorgan failure as rare but potentially fatal, with a recommendation to monitor for signs during early treatment.
What to do: Seek immediate medical attention. (1)
Serious warnings
FDA BOXED WARNING — serious rash (Stevens-Johnson syndrome / toxic epidermal necrolysis) — emergency
Symptoms: The reviewed source describes it only as a life-threatening serious rash, including Stevens-Johnson syndrome and toxic epidermal necrolysis. Any new or worsening rash while taking lamotrigine warrants urgent evaluation.
Action: Seek emergency medical care immediately. Do not wait to see if the rash goes away. Let the emergency clinician evaluate the rash and advise on whether lamotrigine should be continued or stopped. (1)
Hypersensitivity reactions — emergency
Symptoms: Fever or swollen lymph nodes, which may occur even without a rash.
Action: Seek immediate medical evaluation even without a rash. (1)
Suicidal behavior and ideation — urgent
Symptoms: Antiepileptic drugs as a class have been associated with an increased risk of suicidal thoughts or behavior, requiring close monitoring, especially early in treatment.
Action: Contact your prescriber promptly to discuss this. (1)
Withdrawal seizures — urgent
Symptoms: Seizures occurring after abrupt discontinuation.
Action: Do not stop lamotrigine suddenly. Contact your prescriber promptly for instructions after a missed dose or interruption in treatment; no missed-dose guidance was established in the sources reviewed for this page. As with any seizure, seek emergency medical care if it does not stop on its own or an injury occurs. (1)
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Valproate (valproic acid) | Valproate increases lamotrigine blood levels approximately twofold, raising the risk of serious rash. | Lamotrigine dose is reduced by about 50% when used with valproate. Follow the prescriber’s exact titration schedule. (1) |
| Carbamazepine, phenytoin, phenobarbital, primidone (enzyme inducers) | These drugs decrease lamotrigine blood levels by approximately 40%, which may reduce effectiveness. | Higher lamotrigine doses may be required; prescriber will adjust as per standard titration. (1) |
| Estrogen-containing oral contraceptives | During active pill weeks, lamotrigine levels decrease by about 50%; during the pill-free week, levels can increase up to twofold. | Dose adjustments may be needed when starting or stopping oral contraceptives. Inform your prescriber of any contraceptive changes. (1) |
| Rifampin | Rifampin decreases lamotrigine levels by approximately 40%. | Lamotrigine dose may need to be increased; prescriber will monitor. (1) |
Pregnancy, breastfeeding, kidney/liver function, age
Children (ages 2–17)
Lamotrigine is approved for epilepsy adjunctive therapy in children as young as 2 years and for conversion to monotherapy in those 16 years and older. The risk of serious rash is higher in pediatric patients (0.3%–0.8% vs. 0.08%–0.3% in adults). Follow the complete prescribing information. Not approved for Bipolar I Disorder maintenance treatment in patients under 18. (1)
Pregnancy
Lamotrigine was historically classified as Pregnancy Category C. Animal studies did not show teratogenicity, but lamotrigine decreases fetal folate levels. Use during pregnancy only if the potential benefit justifies the risk. Encourage enrollment in the pregnancy registry at 1-888-233-2334 or 1-800-336-2176. (1)
Breastfeeding
Preliminary data indicate lamotrigine passes into breast milk. Breastfeeding is not recommended while taking lamotrigine. (1)
Monitoring
Before starting
- Review all concomitant medications, especially valproate, enzyme inducers, and oral contraceptives.
- Assess for any history of rash or hypersensitivity to antiepileptic drugs.
- The reviewed source reports that blood dyscrasias (neutropenia, thrombocytopenia, pancytopenia) and rare multiorgan failure have occurred; monitor for signs during early treatment.
- Counsel patients on the risk of serious rash and the importance of immediate reporting.
During treatment
- Monitor for any new rash; seek urgent medical evaluation at the first sign, and let the clinician determine whether the rash is drug-related and whether lamotrigine should be continued or discontinued.
- Evaluate any fever, lymphadenopathy, or hypersensitivity symptoms immediately, even without rash.
- Watch for signs of suicidal ideation, especially early in treatment.
- If starting or stopping valproate, enzyme inducers, or oral contraceptives, adjusted lamotrigine dosing as per the label.
- For women of childbearing potential, discuss pregnancy plans and the pregnancy registry.
Storage
No storage instructions for lamotrigine were available in the reviewed source. Follow the dispensing pharmacy or manufacturer’s advice.
Study the drug class: Antiepileptics · Mood stabilisers
Professional information
Clinician-facing context only. Always consult the current local label, especially for dosing in renal/hepatic impairment or pediatric patients.
United States (FDA-approved dosing for immediate-release tablets from the reviewed label)
Indication: Epilepsy adjunctive therapy (patients over 12 years)
Dose summary: Dose depends on concomitant antiepileptic drugs. With valproate: weeks 1–2: 25 mg every other day; weeks 3–4: 25 mg/day; maintenance: 100–200 mg/day. Without valproate and not on enzyme inducers: weeks 1–2: 25 mg/day; weeks 3–4: 50 mg/day; maintenance: 225–375 mg/day. With enzyme inducers (carbamazepine, phenytoin, phenobarbital, primidone) and not on valproate: weeks 1–2: 50 mg/day; weeks 3–4: 100 mg/day; maintenance: 300–500 mg/day. Paediatric epilepsy, ages 2 to 12 years, is weight-based. With valproate: weeks 1-2 0.15 mg/kg/day in 1 or 2 divided doses (round down to the nearest whole tablet); weeks 3-4 0.3 mg/kg/day; then increase every 1 to 2 weeks by 0.3 mg/kg/day; maintenance 1 to 5 mg/kg/day (maximum 200 mg/day), or 1 to 3 mg/kg/day with valproate alone. On enzyme-inducing antiepileptics without valproate: weeks 1-2 0.6 mg/kg/day in 2 divided doses; weeks 3-4 1.2 mg/kg/day; then increase every 1 to 2 weeks by 1.2 mg/kg/day; maintenance 5 to 15 mg/kg/day (maximum 400 mg/day in 2 divided doses).
Renal context: Initial doses should be based on the patient's concomitant medications. Reduced maintenance doses may be effective in significant renal impairment. The label does not specifically address management on dialysis. (1)
United States
Indication: Bipolar I Disorder maintenance (adults ≥18 years)
Dose summary: Target dose depends on concomitant medications. With valproate: target 100 mg/day; titration: weeks 1–2: 25 mg every other day; weeks 3–4: 25 mg/day; week 5: 50 mg/day; week 6: 100 mg/day. Without valproate/enzyme inducers: target 200 mg/day; weeks 1–2: 25 mg/day; weeks 3–4: 50 mg/day; week 5: 100 mg/day; weeks 6–7: 200 mg/day. With enzyme inducers (and not on valproate): target 400 mg/day; weeks 1–2: 50 mg/day; weeks 3–4: 100 mg/day; titrate to 400 mg/day over weeks 5–7.
Renal context: Initial doses should be based on the patient's concomitant medications. Reduced maintenance doses may be effective in significant renal impairment. The label does not specifically address management on dialysis. (1)
Hepatic guidance
No hepatic impairment dosing information was available from the reviewed source.
Frequently asked questions
What should I do if I develop a rash while taking lamotrigine?
Seek immediate medical evaluation for any new rash while taking lamotrigine. Let the clinician you see determine whether the rash is drug-related and advise on whether to continue or stop lamotrigine. Serious rashes like Stevens-Johnson syndrome can be life-threatening. (1)
Can I stop taking lamotrigine suddenly?
No. Sudden discontinuation can cause withdrawal seizures. Lamotrigine should be tapered slowly over at least 2 weeks. A new rash needs urgent medical evaluation; let the clinician you see decide whether faster discontinuation is needed. Follow your prescriber’s instructions. (1)
Is lamotrigine safe during pregnancy?
Lamotrigine was previously classified as Pregnancy Category C. It decreases fetal folate levels. It should be used during pregnancy only if the potential benefit justifies the risk. A pregnancy registry is available to help gather more safety data; ask your doctor about enrolling. (1)
Can I breastfeed while taking lamotrigine?
Breastfeeding is not recommended because lamotrigine passes into breast milk. Discuss your feeding plans with your healthcare provider. (1)
What is the mechanism of action of lamotrigine?
It is classified as an antiepileptic drug (anticonvulsant) and mood stabilizer. (1)
What is the generic name of Lamotrigine?
The generic name is lamotrigine. (1)
What class of drug is lamotrigine?
Lamotrigine is classed as: Anticonvulsant and mood stabilizer. (1)
References
- LAMOTRIGINE TabletsU.S. Food and Drug Administration (DailyMed) · United States · dated Initial U.S. Approval: 1994; label version accessed 2026-08-05 · accessed 2026-08-05 · source 1
- LAMOTRIGINE TABLET, ORALLY DISINTEGRATING [DR. REDDY’S LABORATORIES INC.] — US prescribing information (DailyMed SPL)U.S. National Library of Medicine (DailyMed) · US · accessed 2026-08-14 · source 2
- Lamotrigine — patient drug information (MedlinePlus)U.S. National Library of Medicine (MedlinePlus) · US · accessed 2026-08-14 · source 3
- Lamotrigine — FDA approval record (Drugs@FDA ANDA204158)U.S. Food and Drug Administration · US · accessed 2026-08-14 · source 4
- lamotrigine — RxNorm normalized drug concept (RXCUI 28439)U.S. National Library of Medicine (RxNorm) · US · accessed 2026-08-14 · source 5
Brand names by country
Single-ingredient lamotrigine names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
United States
- LAMICTAL300 mg, 250 mg, 200 mg, 5 mg, 100 mg, 25 mg, 150 mg, 50 mg · glaxosmithkline llc
- SUBVENITE10 mg/mL, 150 mg, 100 mg, 25 mg, 200 mg · owp pharmaceuticals, inc.
Canada
- LAMICTAL