Lamotrigine: Uses, Dosage & Side Effects
A prescription anticonvulsant used for epilepsy and the prevention of depressive episodes in bipolar disorder
Lamotrigine is a prescription anticonvulsant (anti-epileptic) medication used to treat epilepsy and prevent depressive episodes in bipolar disorder. It works primarily by blocking voltage-gated sodium channels in the brain, stabilizing neuronal membranes and reducing the release of excitatory neurotransmitters such as glutamate. Lamotrigine is available under the brand name Lamictal and numerous generic versions. A critical safety concern is the risk of serious, potentially life-threatening skin reactions including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), which is why the dose must always be increased very slowly over several weeks. Never start or change your dose without medical supervision.
Quick Facts: Lamotrigine
Key Takeaways
- Lamotrigine is approved for treating epilepsy (partial and generalized seizures, including Lennox-Gastaut syndrome) in adults and children from age 2, and for preventing depressive episodes in bipolar disorder in adults aged 18 and over.
- Serious, potentially life-threatening skin reactions (Stevens-Johnson syndrome, toxic epidermal necrolysis, DRESS) can occur, especially during the first 8 weeks. The dose must always be started low and increased very gradually to minimize this risk.
- Valproate (valproic acid) approximately doubles lamotrigine blood levels. When taken together, the starting dose and titration schedule must be significantly reduced to prevent toxicity and serious skin reactions.
- Do not stop lamotrigine abruptly if used for epilepsy; the dose must be tapered over approximately 2 weeks to avoid rebound seizures.
- Hormonal contraceptives containing estrogen can significantly reduce lamotrigine levels, potentially reducing its effectiveness. Discuss appropriate contraception with your doctor.
What Is Lamotrigine and What Is It Used For?
Lamotrigine is a prescription medication belonging to the anticonvulsant (anti-epileptic) drug class. First approved in Europe in 1991 and by the U.S. Food and Drug Administration (FDA) in 1994 under the brand name Lamictal, it has become one of the most widely prescribed anti-epileptic drugs worldwide. It is available as a generic medication from many manufacturers, including Lamotrigin Actavis, Lamotrigin Orion, Lamotrigin Bluefish, Lamotrigin Desitin, Lamotrigin Teva, and Lamotrigin 1A Farma. Lamotrigine is listed on the World Health Organization (WHO) Model List of Essential Medicines, reflecting its importance in global healthcare.
Chemically, lamotrigine is a phenyltriazine derivative. Its primary mechanism of action involves blocking voltage-gated sodium channels in neuronal membranes. By stabilizing the inactive state of these channels, lamotrigine prevents the repetitive firing of action potentials that underlies epileptic seizure activity. Additionally, it inhibits the presynaptic release of excitatory neurotransmitters, particularly glutamate and aspartate. This dual mechanism—membrane stabilization and reduced excitatory transmission—accounts for its broad-spectrum anticonvulsant activity. The exact mechanism by which lamotrigine prevents depressive episodes in bipolar disorder is not fully understood, but it is thought to be related to its modulation of glutamate release and effects on neural circuits involved in mood regulation.
Epilepsy
Lamotrigine is approved for the treatment of epilepsy in both adults and children. In adults and adolescents aged 13 years and older, it can be used as monotherapy (sole treatment) or as adjunctive therapy (add-on to other anti-epileptic drugs) for partial (focal) seizures with or without secondary generalization and for primary generalized tonic-clonic seizures. It is also effective as adjunctive therapy for seizures associated with Lennox-Gastaut syndrome, a severe childhood-onset epilepsy characterized by multiple seizure types and intellectual disability.
In children aged 2 to 12 years, lamotrigine is approved as adjunctive therapy for partial seizures, generalized seizures, and seizures associated with Lennox-Gastaut syndrome. It can also be used as monotherapy for the treatment of typical absence seizures in this age group. Lamotrigine is not recommended for children under 2 years of age due to limited safety and efficacy data.
Clinical trials and extensive real-world experience have established lamotrigine as a first-line treatment for many types of epilepsy. It is particularly valued for its broad spectrum of activity, favorable cognitive profile (it tends to cause less cognitive impairment than many older anti-epileptic drugs), and relatively good tolerability. The International League Against Epilepsy (ILAE) and NICE guidelines recommend lamotrigine as a first-line option for focal epilepsy and as a treatment option for generalized epilepsy, including absence seizures and juvenile myoclonic epilepsy.
Bipolar Disorder
In adults aged 18 years and older, lamotrigine is approved for the prevention of depressive episodes in bipolar disorder (previously known as manic-depressive illness). Bipolar disorder is characterized by extreme mood swings, alternating between periods of mania (elevated mood, increased energy, reduced need for sleep) and depression (persistent sadness, loss of interest, fatigue). Lamotrigine is primarily effective at preventing the depressive pole of the illness rather than manic episodes.
It is important to understand that lamotrigine is used as a maintenance treatment (long-term prevention) for bipolar depression, not as an acute treatment for an ongoing depressive or manic episode. The slow titration required for safety reasons means it takes several weeks to reach therapeutic doses. NICE and American Psychiatric Association (APA) guidelines recommend lamotrigine as a first-line maintenance therapy for bipolar disorder, particularly for patients in whom depressive episodes predominate. It can be used alone or in combination with other mood stabilizers such as lithium.
Lamotrigine is available in two main formulations: standard tablets (25 mg, 50 mg, 100 mg, and 200 mg) and chewable/dispersible tablets (2 mg, 5 mg, 25 mg, 50 mg, 100 mg, and 200 mg). The chewable/dispersible tablets can be swallowed whole, chewed, or dissolved in water to create a liquid, making them suitable for patients who have difficulty swallowing tablets, including children. Both formulations are taken orally, once or twice daily, with or without food.
What Should You Know Before Taking Lamotrigine?
Contraindications
Lamotrigine must not be used if you have a known allergy (hypersensitivity) to lamotrigine or any of the other ingredients in the formulation. If you have previously experienced Stevens-Johnson syndrome or toxic epidermal necrolysis while taking lamotrigine, you must never use this medication again. A previous serious skin reaction to lamotrigine is an absolute contraindication to re-challenge, as the risk of recurrence is extremely high and potentially fatal.
You should also ensure you are not already taking another medication that contains lamotrigine, as accidental duplication could lead to overdose and increased risk of adverse effects. Always check with your pharmacist if you are unsure whether any of your current medications contain lamotrigine.
Warnings and Precautions
A small number of people taking lamotrigine develop serious, potentially life-threatening allergic reactions or skin reactions including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS). These are most likely during the first 8 weeks of treatment, especially if the dose is started too high or increased too quickly, or if lamotrigine is taken with valproate. Seek immediate medical attention if you develop a rash, skin blistering, mouth sores, fever, or swollen lymph nodes.
Talk to your doctor before taking lamotrigine if any of the following apply to you:
- Kidney problems: Impaired kidney function may affect how lamotrigine is eliminated from your body, potentially requiring dose adjustments.
- Previous skin rash with lamotrigine or other anti-epileptic drugs: A history of rash with similar medications increases the risk of developing a rash with lamotrigine.
- Photosensitivity: Some patients experience rash or sunburn-like reactions when exposed to sunlight or artificial UV light (such as tanning beds) while taking lamotrigine. Your doctor may recommend sun protection measures.
- Previous meningitis with lamotrigine: Aseptic meningitis (inflammation of the brain membranes) has been reported rarely with lamotrigine. If you experienced this previously, discuss it with your doctor.
- Brugada syndrome or other heart conditions: Brugada syndrome is a genetic condition that causes abnormal electrical activity in the heart. Lamotrigine may trigger ECG abnormalities that can lead to arrhythmias (abnormal heart rhythms) in susceptible individuals.
- Asian heritage (particularly Han Chinese or Thai): The risk of serious skin reactions may be associated with a genetic variant (HLA-B*1502) that is more common in people of Asian descent. If you have this heritage and have previously tested positive for this variant, discuss it with your doctor before starting lamotrigine.
Reports of a rare but very serious immune system reaction called hemophagocytic lymphohistiocytosis (HLH) have been received in patients taking lamotrigine. Contact your doctor immediately if you experience fever, rash, neurological symptoms (such as tremor, confusion, or impaired brain function).
Anti-epileptic drugs, including lamotrigine, have been associated with a small increased risk of suicidal thoughts and behavior. This risk may be higher when starting treatment, if you have previously had suicidal thoughts, or if you are under 25 years old. Contact your doctor immediately if you experience worsening mood, new or worsening depression, or thoughts of self-harm. Lamotrigine should not be used for bipolar disorder in patients under 18 years of age.
If you take lamotrigine for epilepsy, be aware that seizures may occasionally become worse or occur more frequently during treatment. Some patients may experience severe seizures that can cause serious health problems. Contact your doctor promptly if your seizure pattern changes or worsens.
Pregnancy and Breastfeeding
If you are pregnant, think you may be pregnant, or are planning to become pregnant, consult your doctor before using lamotrigine. You should never stop your anti-epileptic treatment without medical advice, especially if you have epilepsy, as uncontrolled seizures pose serious risks to both you and your baby.
Pregnancy can alter the effectiveness of lamotrigine; blood levels may drop significantly during pregnancy (particularly in the second and third trimesters), which may necessitate dose increases. Your doctor will likely monitor your lamotrigine blood levels regularly and adjust the dose as needed. After delivery, lamotrigine levels may rise again, requiring a dose reduction.
There may be a small increased risk of birth defects, including cleft lip or cleft palate, if lamotrigine is taken during the first three months of pregnancy. However, among anti-epileptic drugs, lamotrigine is generally considered to have one of the lower risks of major congenital malformations. Data from pregnancy registries suggest a malformation rate of approximately 2-3% with lamotrigine monotherapy, which is only slightly higher than the background rate of 2-3% in the general population. Your doctor may recommend that you take supplemental folic acid before and during pregnancy to help reduce the risk of neural tube defects.
Lamotrigine passes into breast milk and may affect the nursing infant. Your doctor will discuss the benefits and risks of breastfeeding during lamotrigine treatment. If you choose to breastfeed, the infant should be monitored for signs of drowsiness, poor feeding, rash, or poor weight gain.
Driving and Operating Machinery
Lamotrigine may cause dizziness, blurred vision, or double vision. Do not drive or operate machinery unless you are confident that your reactions are not affected. If you have epilepsy, also discuss with your doctor whether it is safe for you to drive, as local laws and regulations regarding driving with epilepsy vary by country.
How Does Lamotrigine Interact with Other Drugs?
Drug interactions are a critical consideration when taking lamotrigine, as several commonly used medications can dramatically alter its blood levels. Lamotrigine is primarily metabolized in the liver through glucuronidation (conjugation with glucuronic acid), and medications that inhibit or induce this metabolic pathway can significantly change how much lamotrigine is in your bloodstream. This directly affects both effectiveness and the risk of side effects, including serious skin reactions.
Major Interactions
| Drug | Effect on Lamotrigine | Clinical Significance |
|---|---|---|
| Valproate (valproic acid) | Approximately doubles lamotrigine levels | Starting dose and titration must be halved. Maintenance dose typically 100-200 mg/day. Significantly increased risk of SJS/TEN without proper dose adjustment. |
| Carbamazepine | Reduces lamotrigine levels by ~40% | Higher lamotrigine doses may be needed. Faster titration schedule. Monitor for CNS side effects (dizziness, ataxia, diplopia). |
| Phenytoin | Reduces lamotrigine levels by ~40-50% | Higher lamotrigine doses typically required. Use enzyme-inducing titration schedule. |
| Phenobarbital / Primidone | Reduces lamotrigine levels by ~40% | Higher doses required. Use enzyme-inducing titration schedule. |
| Rifampicin | Significantly reduces lamotrigine levels | Dose increase likely necessary. Monitor lamotrigine levels during and after rifampicin treatment. |
| Hormonal contraceptives (estrogen-containing) | Can reduce lamotrigine levels by ~50% | Seizure control or mood stability may worsen. Dose adjustment may be needed. Discuss alternative contraception with your doctor. |
| Lopinavir/Ritonavir | Reduces lamotrigine levels by ~50% | Lamotrigine dose increase likely necessary during HIV treatment. |
| Atazanavir/Ritonavir | Reduces lamotrigine levels | Dose adjustment may be required. Monitor for reduced efficacy. |
Other Notable Interactions
Several other medications may interact with lamotrigine, though the clinical significance is generally less pronounced than the major interactions listed above:
- Oxcarbazepine, felbamate, gabapentin, levetiracetam, pregabalin, topiramate, zonisamide: These anti-epileptic drugs do not significantly affect lamotrigine levels, but your doctor needs to know about them to ensure you are taking the correct dose.
- Lithium, olanzapine, aripiprazole: Used to treat mental health conditions. Generally no significant pharmacokinetic interaction, but inform your doctor as combined use requires monitoring.
- Bupropion: Used for depression and smoking cessation. No significant interaction, but inform your doctor.
- Paracetamol (acetaminophen): High-dose or regular use may slightly reduce lamotrigine levels. Occasional use at standard doses is generally safe.
- Risperidone: Used to treat mental health conditions. A study has reported increased drowsiness when combined with lamotrigine, but no significant pharmacokinetic interaction.
- Hormone replacement therapy (HRT): Estrogen-containing HRT may reduce lamotrigine blood levels. Your doctor may monitor your lamotrigine levels if you start, stop, or change HRT.
Estrogen-containing hormonal contraceptives (such as combined oral contraceptive pills) can reduce lamotrigine blood levels by approximately 50%, potentially leading to loss of seizure control or return of depressive episodes. Conversely, lamotrigine may also reduce the effectiveness of hormonal contraceptives, though this is less well established. Your doctor may recommend alternative contraception methods (such as progestogen-only pills, IUD, or barrier methods) or adjust your lamotrigine dose. If you experience changes in your menstrual cycle while taking both medications, discuss this with your doctor as it may indicate an interaction.
What Is the Correct Dosage of Lamotrigine?
It may take some time to find the lamotrigine dose that works best for you. The dose depends on your age, whether you are taking lamotrigine alone or with other medications, and whether you have any kidney or liver problems. Your doctor will start you on a low dose and increase it gradually over several weeks until you reach an effective maintenance dose. Never take more lamotrigine than your doctor has prescribed, and never increase the dose on your own, as doing so significantly increases the risk of serious skin reactions.
Adults (13 Years and Older) — Epilepsy
| Period | Without Valproate or Enzyme Inducers | With Valproate | With Enzyme Inducers (no Valproate) |
|---|---|---|---|
| Weeks 1-2 | 25 mg once daily | 12.5 mg once daily | 50 mg once daily |
| Weeks 3-4 | 50 mg once daily | 25 mg once daily | 100 mg daily (in 2 divided doses) |
| Weeks 5 onwards | Increase by 50-100 mg every 1-2 weeks | Increase by 25-50 mg every 1-2 weeks | Increase by 100 mg every 1-2 weeks |
| Maintenance dose | 100-400 mg/day (1-2 doses) | 100-200 mg/day (1-2 doses) | 200-400 mg/day (in 2 divided doses) |
Children (2-12 Years) — Epilepsy
For children aged 2 to 12 years, the effective dose depends on body weight and typically ranges from 1 to 15 mg per kilogram of body weight per day, up to a maximum maintenance dose of 200 mg daily. The titration is even more gradual in children, and the dose is always determined by the prescribing physician based on the child's weight and concomitant medications. Children taking valproate require substantially lower starting and maintenance doses.
Lamotrigine is not recommended for children under 2 years of age due to insufficient safety and efficacy data in this population.
Adults (18 Years and Older) — Bipolar Disorder
The titration schedule for bipolar disorder follows the same general principles as for epilepsy. The typical maintenance dose is 200 mg/day when lamotrigine is taken without valproate or enzyme-inducing drugs, 100 mg/day with valproate, and up to 400 mg/day with enzyme-inducing drugs. The dose must still be started low and increased slowly over several weeks. It may take several weeks to months before the full mood-stabilizing benefit is felt.
Elderly Patients
No specific dose adjustment is required based on age alone. However, elderly patients are more likely to have impaired kidney or liver function, which may affect lamotrigine metabolism. They may also be more sensitive to side effects such as dizziness and impaired coordination, increasing the risk of falls. Dose titration should be cautious, and lower maintenance doses may be appropriate.
How to Take Lamotrigine
Take your lamotrigine dose once or twice daily as directed by your doctor. It can be taken with or without food. Standard tablets should be swallowed whole with water; do not split, chew, or crush them. Chewable/dispersible tablets can be swallowed whole with water, chewed (drink a small amount of water at the same time), or dissolved in a glass of water to make a liquid medication. If making a liquid, add the tablet to a glass with enough water to cover it, wait until it dissolves completely, stir, and drink the entire contents. Add a little more water to the glass and drink that too, to ensure you take the full dose.
Missed Dose
If you forget to take a dose, do not take a double dose to make up for it. Simply take your next dose at the usual time. If you have missed several doses, consult your doctor before resuming treatment, as it may be necessary to re-titrate the dose gradually rather than resume at your previous maintenance dose. This is because the risk of serious skin reactions can increase if lamotrigine is restarted at a full dose after a gap in treatment.
Overdose
If you or someone else has taken too much lamotrigine, contact emergency services or a poison control center immediately. Overdose symptoms may include: rapid uncontrolled eye movements (nystagmus), impaired coordination and balance (ataxia), changes in heart rhythm (detectable on ECG), loss of consciousness, seizures (convulsions), and coma.
Stopping Lamotrigine
If you take lamotrigine for epilepsy, it is critical that you do not stop taking it suddenly. Abrupt discontinuation can cause your epilepsy to return or worsen, potentially leading to dangerous rebound seizures including status epilepticus. The dose should be reduced gradually over approximately 2 weeks under medical supervision.
If you take lamotrigine for bipolar disorder, it may take time for the medication to work, and you may not notice improvement immediately. While gradual dose reduction is not strictly necessary for safety, you should still consult your doctor before stopping treatment, as depressive episodes may return.
What Are the Side Effects of Lamotrigine?
Like all medicines, lamotrigine can cause side effects, although not everyone will experience them. Understanding the potential side effects and their frequency helps you recognize when to seek medical attention and when symptoms are likely to be manageable.
A small number of people taking lamotrigine develop serious allergic reactions or skin reactions that can be life-threatening if not treated promptly. These are most likely during the first months of treatment, especially if the dose is started too high or increased too quickly, or if you are also taking valproate. Children may be at higher risk. Warning signs include:
- Skin rash or redness, which may develop into blistering and peeling skin, particularly around the mouth, nose, eyes, and genitals (SJS/TEN)
- Target-like marks on the skin (erythema multiforme)
- Mouth sores, sore throat, or red/swollen eyes (conjunctivitis)
- Fever, flu-like symptoms, or extreme drowsiness
- Swelling of the face or swollen glands in the neck, armpits, or groin
- Unexpected bleeding, bruising, or blue fingers
- Elevated liver enzyme levels or organ dysfunction
Very Common
May affect more than 1 in 10 people
- Headache
- Skin rash
Common
May affect up to 1 in 10 people
- Aggression or irritability
- Drowsiness or sleepiness
- Dizziness
- Tremor (shaking)
- Difficulty sleeping (insomnia)
- Agitation
- Diarrhea
- Dry mouth
- Nausea and vomiting
- Fatigue
- Back pain, joint pain, or pain elsewhere
Uncommon
May affect up to 1 in 100 people
- Impaired coordination (ataxia)
- Double vision or blurred vision
- Hair loss or thinning (alopecia)
- Photosensitivity (rash or sunburn from sun or artificial light exposure)
Rare
May affect up to 1 in 1,000 people
- Erythema multiforme (target-like skin rash)
- Stevens-Johnson syndrome (SJS) — a life-threatening skin reaction
- Aseptic meningitis (fever, headache, neck stiffness, sensitivity to light) — usually resolves when lamotrigine is stopped
- Rapid uncontrolled eye movements (nystagmus)
- Itchy eyes with discharge and crusting (conjunctivitis)
Very Rare
May affect up to 1 in 10,000 people
- Toxic epidermal necrolysis (TEN) — extensive skin peeling
- DRESS syndrome (Drug Reaction with Eosinophilia and Systemic Symptoms)
- Fever, facial swelling, swollen lymph nodes
- Changes in liver function or liver failure
- Disseminated intravascular coagulation (a serious blood clotting disorder)
- Hemophagocytic lymphohistiocytosis (HLH)
- Blood disorders: anemia, low white blood cells (leukopenia, neutropenia, agranulocytosis), low platelets (thrombocytopenia), pancytopenia, aplastic anemia
- Hallucinations (seeing or hearing things that are not there)
- Confusion
- Unsteadiness when moving
- Tics, involuntary movements (choreoathetosis), or muscle spasms
- Increased seizure frequency in people with existing epilepsy
- Worsening of Parkinson's disease symptoms
- Lupus-like reaction (joint and back pain, sometimes with fever)
Other Reported Side Effects (Frequency Unknown)
- Bone effects including osteopenia and osteoporosis (bone thinning) and fractures, particularly with long-term anti-epileptic use
- Kidney inflammation (tubulointerstitial nephritis), sometimes with eye inflammation (uveitis)
- Nightmares
- Reduced immune function due to lower immunoglobulin levels
- Pseudolymphoma (red nodules or patches on the skin)
Many of the symptoms listed above may indicate a less serious side effect. However, you must be aware that some can be signs of life-threatening reactions. If you develop any rash, skin blistering, mouth sores, fever, or swollen glands while taking lamotrigine, contact your doctor immediately. Your doctor may decide to test your liver, kidneys, or blood and may tell you to stop taking lamotrigine.
How Should You Store Lamotrigine?
Keep lamotrigine out of the sight and reach of children at all times. Store the medication in its original packaging to protect it from moisture and light. There are no special temperature requirements for lamotrigine tablets; standard room temperature storage is appropriate.
Do not use lamotrigine after the expiration date (EXP) printed on the blister pack, carton, or bottle. The expiration date refers to the last day of that month. Medicines should not be disposed of via wastewater or household waste. Ask your pharmacist how to properly dispose of medicines you no longer use. These measures help protect the environment.
What Does Lamotrigine Contain?
Standard Tablets
The active substance is lamotrigine. Each tablet contains 25 mg, 50 mg, 100 mg, or 200 mg of lamotrigine. The other (inactive) ingredients are: lactose monohydrate, microcrystalline cellulose, povidone K30, sodium starch glycolate (type A), yellow iron oxide (E172), and magnesium stearate. The tablets are square with rounded corners and pale yellow-brown in color.
Note: Lamotrigine standard tablets contain small amounts of lactose. If you have been told by your doctor that you have an intolerance to certain sugars, contact your doctor before taking this medicine. The tablets contain less than 1 mmol (23 mg) of sodium per tablet, meaning they are essentially sodium-free.
Chewable/Dispersible Tablets
Each chewable/dispersible tablet contains 2 mg, 5 mg, 25 mg, 50 mg, 100 mg, or 200 mg of lamotrigine. The other ingredients are: calcium carbonate, low-substituted hydroxypropyl cellulose, aluminum magnesium silicate, sodium starch glycolate (type A), povidone K30, saccharin sodium, magnesium stearate, and blackcurrant flavoring. The tablets are white to off-white and may be slightly marbled, with a blackcurrant smell.
Frequently Asked Questions About Lamotrigine
Lamotrigine is used to treat two main conditions: epilepsy and bipolar disorder. For epilepsy, it is effective against partial (focal) seizures, generalized tonic-clonic seizures, absence seizures, and seizures associated with Lennox-Gastaut syndrome. It can be used in adults and children from age 2 (with age-dependent prescribing guidelines). For bipolar disorder, it is used in adults aged 18 and over specifically to prevent the depressive episodes that characterize the condition. It is not used as an acute treatment for mania or depression already in progress.
Lamotrigine can cause rare but potentially life-threatening skin reactions including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS). These typically occur within the first 8 weeks of treatment, particularly if the dose is started too high, increased too quickly, or if taken with valproate. Warning signs include widespread rash, skin blistering and peeling (especially around the mouth, nose, eyes, and genitals), mouth sores, fever, and swollen lymph nodes. If you experience any of these, stop taking lamotrigine and seek immediate medical attention.
Lamotrigine must be started at a low dose and increased very gradually (a process called titration) to minimize the risk of serious and potentially fatal skin reactions such as Stevens-Johnson syndrome and toxic epidermal necrolysis. Research has clearly shown that rapid dose escalation is a major risk factor for these reactions. The titration schedule varies depending on whether you are also taking valproate (which requires an even slower titration) or enzyme-inducing drugs such as carbamazepine or phenytoin. It typically takes 5-7 weeks to reach a full maintenance dose. Never increase the dose faster than your doctor has advised.
Lamotrigine use during pregnancy requires careful medical supervision and individual risk-benefit assessment. Among anti-epileptic drugs, lamotrigine is generally considered to have one of the lower risks of birth defects. However, there is a small increased risk of cleft lip or palate when taken during the first trimester. Importantly, you should never stop anti-epileptic medication abruptly during pregnancy, as uncontrolled seizures can be dangerous for both mother and baby. Pregnancy hormones can significantly reduce lamotrigine blood levels, often requiring dose increases during pregnancy and dose reductions after delivery. Folic acid supplementation is usually recommended before and during pregnancy.
Valproate (valproic acid) significantly inhibits the liver enzymes that metabolize lamotrigine, approximately doubling its blood levels and half-life. This means that when lamotrigine is taken together with valproate, the starting dose must be halved and the dose must be increased much more slowly to prevent dangerously high levels and the associated risk of serious skin reactions such as SJS and TEN. The typical maintenance dose of lamotrigine when combined with valproate is 100-200 mg per day, compared to 200-400 mg per day without valproate. Your doctor will use a specific, slower titration schedule designed for this combination.
If you take lamotrigine for epilepsy, you should never stop it suddenly. Abrupt discontinuation can cause seizures to return or worsen, including potentially dangerous rebound seizures and even status epilepticus (prolonged seizures). The dose should be reduced gradually over approximately two weeks under medical supervision. If you take lamotrigine for bipolar disorder, abrupt stopping does not carry the same seizure risk, but you should still discuss it with your doctor before stopping, as depressive episodes may return. In all cases, any changes to your lamotrigine treatment should be made under medical guidance.
References
- World Health Organization (WHO). WHO Model List of Essential Medicines — 23rd List, 2023. Geneva: WHO; 2023. Lamotrigine is listed as an essential anti-epileptic medicine.
- European Medicines Agency (EMA). Lamictal (Lamotrigine) — Summary of Product Characteristics (SmPC). European public assessment report. Last updated 2025.
- U.S. Food and Drug Administration (FDA). Lamictal (Lamotrigine) — Full Prescribing Information. Reference ID: 5268750. Revised 2024.
- National Institute for Health and Care Excellence (NICE). Epilepsies in Children, Young People and Adults (NG217). NICE Guideline, updated 2024.
- National Institute for Health and Care Excellence (NICE). Bipolar Disorder: Assessment and Management (CG185). NICE Clinical Guideline, updated 2023.
- British National Formulary (BNF). Lamotrigine. NICE Evidence Services. Accessed January 2026.
- Mosholder AD, Gelperin K, Hammad TA, Phelan K, Johann-Liang R. Hallucinations and other psychotic symptoms associated with the use of attention-deficit/hyperactivity disorder drugs in children. Pediatrics. 2009;123(2):611-616.
- Tomson T, Battino D, Bonizzoni E, et al. Comparative risk of major congenital malformations with eight different antiepileptic drugs: a prospective cohort study of the EURAP registry. Lancet Neurol. 2018;17(6):530-538. doi:10.1016/S1474-4422(18)30107-8
- Guberman AH, Besag FM, Brodie MJ, et al. Lamotrigine-associated rash: risk/benefit considerations in adults and children. Epilepsia. 1999;40(7):985-991.
- Geddes JR, Calabrese JR, Goodwin GM. Lamotrigine for treatment of bipolar depression: independent meta-analysis and meta-regression of individual patient data from five randomised trials. Br J Psychiatry. 2009;194(1):4-9. doi:10.1192/bjp.bp.107.048504
Editorial Team
This article has been written and reviewed by the iMedic Medical Editorial Team, comprising licensed specialist physicians in neurology, psychiatry, and clinical pharmacology. All content is based on current international guidelines (WHO, EMA, FDA, NICE, BNF) and peer-reviewed research. The team follows the GRADE evidence framework and has no conflicts of interest or commercial funding.
iMedic Medical Editorial Team — Specialists in neurology, psychiatry, and clinical pharmacology with expertise in anti-epileptic and mood-stabilizing medications.
iMedic Medical Review Board — Independent panel of medical experts who review all content according to international guidelines and the GRADE evidence framework.
Evidence Level: 1A — Based on systematic reviews, meta-analyses of randomized controlled trials, and international clinical guidelines. Last reviewed: .