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EspañolLamictal (generic: lamotrigine) is a brand-name prescription drug that is approved by the U.S. Food and Drug Administration (FDA) to treat epilepsy in adults and children, as well as bipolar I disorder in adults. The active ingredient is lamotrigine, which is available as a generic drug. This drug is classified as an antiepileptic drug (AED) and mood-stabilizing agent (MSA). In addition to its FDA-approved indications, it is often prescribed for other mood disorders and for the prevention of migraine headaches.
RELATED: Bipolar disorder treatment and medications
Lamictal forms and strengths
Lamictal tablets are available in immediate-release (Lamictal), chewable dispersible (Lamictal), orally disintegrating (Lamictal ODT), or extended-release (Lamictal XR) forms.
Tablets: 25 mg, 100 mg, 150 mg, 200 mg
Extended-release tablets: 25 mg, 50 mg, 100 mg, 200 mg, 250 mg, 300 mg
Chewable dispersible tablets: 2 mg, 5 mg, 25 mg
Orally disintegrating tablets: 25 mg, 50 mg, 100 mg, 200 mg
Lamictal dosage for adults
Lamictal is approved for use in adults to treat epilepsy and bipolar I disorder.
Lamictal dosage chart |
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|---|---|---|---|
| Indication | Starting dosage | Standard dosage | Maximum dosage |
| Bipolar I disorder (monotherapy) | 25 mg by mouth daily for two weeks, then 50 mg daily for 2 weeks, then 100 mg daily for 1 week | 200 mg by mouth daily | 200 mg per day |
| Partial seizures (monotherapy following treatment with a different antiepileptic monotherapy regimen) | Initial titration schedule depends on the AED being replaced. Lamotrigine dose will be increased while previous AED is decreased. See package insert for detailed instructions. | Immediate-release tablets: 250 mg by mouth twice daily Extended-release tablets: 250-300 mg per day | 400 mg per day/ 200 mg when used with valproate alone |
| Lennox-Gastaut syndrome (used in combination with valproate) | 25 mg by mouth every other day for two weeks, then 25 mg daily for two weeks, then 50 mg daily for one week, then increase by 25-50 mg daily every one to two weeks | 100-400 mg per day as one dose or divided into two doses | 400 mg per day/ 200 mg when used with valproate alone |
| Tonic clonic seizures (used in combination with valproate) | 25 mg by mouth every other day for two weeks, then 25 mg daily for two weeks, then 50 mg daily for one week, then increase by 25-50 mg daily every one to two weeks | Immediate-release tablets: 100-400 mg per day as one dose or divided into two doses Extended-release tablets: 200-250 mg by mouth once daily | 400 mg per day/ 200 mg when used with valproate alone |
| Prevention of migraine with aura | 25 mg by mouth daily for two weeks, may increase by 25 mg each week | 100 mg daily | 100 mg daily |
Lamictal dosage for bipolar I disorder
Lamotrigine is a first-line treatment for acute depressive episodes in bipolar I disorder due to its effectiveness for acute depressive episodes. Lamotrigine delays the time to relapse of mood episodes as well as the onset of new depressive episodes. It is believed that lamotrigine’s effects stem from its ability to reduce the effects of a neurotransmitter called glutamate while increasing the release of another neurotransmitter called gamma-aminobutyric acid (GABA).
Lamotrigine can be used by itself or in combination with other medications for the treatment of bipolar I disorder. When used by itself (monotherapy), lamotrigine is started at 25 mg daily for two weeks, then increased to 50 mg (as one dose or divided into two doses 12 hours apart) for another two weeks, then increased again to 100 mg daily during week five. The target dose is 200 mg daily (once a day or divided into two doses). When taken with other medications, this regimen may need to be decreased or increased, depending on the medicines. For example, when taking lamotrigine with valproate, the dose is reduced by half. When taken with certain mood stabilizers such as carbamazepine, the dose is doubled.
Lamictal dosage for epilepsy
Lamotrigine is FDA-approved to treat epilepsy, specifically simple and complex partial seizures, generalized seizures of Lennox-Gastaut syndromes (LGS), and primary generalized tonic-clonic seizures in adults. It is only approved as monotherapy for partial seizures after carbamazepine, phenytoin, phenobarbital, primidone, or valproate has been used as monotherapy previously.
Lamotrigine is not approved for initial monotherapy for partial seizures. It is only approved for use alongside valproate or other antiepileptic drugs (AED) for tonic-clonic seizures and LGS. When used with valproate, the starting dose is 25 mg by mouth every other day for two weeks, then 25 mg daily for two weeks, then 50 mg daily for one week, then increased by 25-50 mg daily every one to two weeks. The target dose is 100-400 mg daily of the immediate-release tablets or 200-250 mg daily of the extended-release tablets. The starting dose, target dose, and maximum dose differ when taking lamotrigine with AEDs other than valproic acid.
Lamictal dosage for prevention of migraines
While not approved by the FDA for preventing migraines, medical literature demonstrates that lamotrigine may be effective at reducing migraines with aura, although data is conflicting. The starting dose for immediate-release tablets is 25 mg daily for two weeks, which may be increased by 25 mg/daily every week until the target dose of 100 mg daily is reached. While it is commonly prescribed for migraine prevention, it should be noted that the American Academy of Neurology, the American Headache Society, and American Family Physician guidelines classify lamotrigine as an ineffective treatment for migraine prevention.
Lamictal dosage for children
The following dosing regimens listed are for children taking lamotrigine with valproate. For patients taking lamotrigine with alternative antiepileptic drugs (AEDs) who are not taking valproate, dosing regimens depend on the specific AEDs being used.
Standard Lamictal maintenance treatment for children ages 2-12 years old taking
valproate: 1 to 5 mg/kg/day (maximum 200 mg/day in 1 or 2 divided doses) if valproate and other AEDs are being used with lamotrigine. 1 to 3 mg/kg/day if using valproate and lamotrigine alone. Maintenance doses in patients weighing less than 30 kg, regardless of age or concomitant AED, may need to be increased as much as 50%, based on clinical response.
Standard Lamictal maintenance treatment for children ages 13 and older taking valproate: 100 to 400 mg/day (1 or 2 divided doses) if valproate and other AEDs are being used with lamotrigine. 100 to 200 mg/day if using valproate and lamotrigine alone.
Immediate-release lamotrigine tablets are FDA-approved in children as young as 2 years old when it is given as part of a combination of seizure medications. However, this form is not FDA-approved for use as a single medication in a child or teenager who is younger than 16 years old.
Extended-release lamotrigine tablets are only FDA-approved for use in children who are at least 13 years old.
Lamictal dosage by weight/age |
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|---|---|---|
| Indication | Age group | Recommended dosage* |
| Partial seizures (used in combination with valproate) | 2-12 years old | 0.15 mg/kg/day divided into one or two doses for two weeks, then 0.3 mg/kg/day divided into one or two doses for two weeks, then increase by 0.3 mg/kg/day every one to two weeks. Max 200 mg/day. Round down to the nearest whole tablet size. |
| Partial seizures (used in combination with valproate) | 13 years or older | 25 mg by mouth every other day for two weeks, then 25 mg daily for two weeks, then 50 mg daily for one week, then increase by 25-50 mg/day every one to two weeks. Max 400 mg/day. |
| Lennox-Gastaut syndrome (used in combination with valproate) | 2-12 years old | 0.15 mg/kg/day divided into one or two doses for two weeks, then 0.3 mg/kg/day divided into one or two doses for two weeks, then increase by 0.3 mg/kg/day every one to two weeks. Max 200 mg/day. Round down to the nearest whole tablet size. |
| Lennox-Gastaut syndrome (used in combination with valproate) | 13 years or older | 25 mg by mouth every other day for two weeks, then 25 mg daily for two weeks, then 50 mg daily for one week, then increase by 25-50 mg/day every one to two weeks. Max 400 mg/day, 200mg/day if using valproate and lamotrigine alone. |
| Tonic clonic seizures (used in combination with valproate) | 2-12 years old | 0.15 mg/kg/day divided into one or two doses for two weeks, then 0.3 mg/kg/day divided into one or two doses for two weeks, then increase by 0.3 mg/kg/day every one to two weeks. Max 200 mg/day. Round down to the nearest whole tablet size. |
| Tonic clonic seizures (used in combination with valproate) | 13 years or older | Immediate-release: 25 mg by mouth every other day for two weeks, then 25 mg daily for two weeks, then 50 mg daily for one week, then increase by 25 – 50 mg daily every one to two weeks. Max of 400 mg/day, or 200mg/day if using valproate and lamotrigine alone. Extended-release: 25 mg every other day for two weeks, then 25 mg daily for two weeks, then 50 mg daily for one week, then increase by 50 mg/day every week for two weeks, then increase by up to 100 mg/day every week. |
* To convert pounds to kilograms, divide the child’s weight in pounds by 2.2.
Lamictal dosage restrictions
Lamictal (lamotrigine) should not be used in patients with a history of a severe hypersensitivity reaction to lamotrigine or any of the ingredients in Lamictal (lamotrigine) tablets. An example of a severe hypersensitivity reaction is anaphylaxis, which is characterized by difficulty breathing, skin rash, and/or swelling of the face, tongue, or throat.
Patients with poor kidney function require a reduction in their lamotrigine dosage. Patients with a creatinine clearance less than 10 mg/mL, patients on hemodialysis, and patients on peritoneal dialysis typically use 50% of the usual recommended dose.
Patients with moderate to severe hepatic impairment (liver impairment) require a 25% decrease in lamotrigine dose compared to the standard recommended dosage. Patients with severe liver impairment with ascites require a 50% decrease in dose compared to standard recommended doses.
How to take Lamictal
Take your medicine as directed. Your dose may need to be changed several times to find what works best for you.
Lamotrigine can be taken with food or without food, but it is best to be consistent—if you usually take lamotrigine with food, try to do that all the time, as food may affect the way the medicine is absorbed.
Chewable tablet or tablet for suspension: You may swallow the tablet whole, or you may chew it and then swallow a small amount of water or diluted fruit juice. You may also dissolve the chewable tablet. To do this, put about 1 teaspoon of water or juice in a glass, drop in the tablet, let it sit for about 1 minute so it dissolves, swirl the glass to mix, and then swallow the entire mixture.
Disintegrating tablet: Make sure your hands are dry before you handle the tablet. Place the tablet on your tongue. Move the tablet around in your mouth so it dissolves.
Regular tablet: Swallow the tablet whole. You may break or crush the tablet if your doctor tells you to, but the medicine might leave a bitter taste in your mouth.
Swallow the extended-release tablet whole. Do not crush, break, or chew it.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Do not use it if the blister pack is torn or broken.
Birth control pills can make lamotrigine less effective, resulting in increased seizures. Tell your doctor if you start or stop using birth control pills. Your lamotrigine dose may need to be changed.
Do not stop using lamotrigine suddenly, even if you feel fine. Stopping suddenly may cause increased seizures.
Do not start or stop taking seizure medication during pregnancy without your doctor's advice. Having a seizure during pregnancy could harm both mother and baby. Tell your doctor right away if you become pregnant. Follow your doctor's instructions about tapering your dose.
Lamictal dosage FAQs
How long does it take Lamictal to work?
A single dose of lamotrigine reaches its peak concentration in the bloodstream one to three hours after ingestion, but its effects may not be noticeable if you are just beginning treatment or are restarting treatment at a low dose. It can take up to six weeks for lamotrigine to work effectively against seizures and can take several weeks to have noticeable effects as a mood stabilizer. One of the reasons it takes this long for lamotrigine to work is the need to start at small doses and gradually increase to an effective dose. This method reduces adverse reactions such as headaches, drowsiness, irritability, tremors, and difficulty sleeping.
How long does Lamictal stay in your system?
Healthcare professionals measure the time it takes to eliminate a drug from the body using a metric called a half-life; this is the time it takes the body to get rid of half the amount of drug currently in your system.
The half-life of lamotrigine depends on several factors such as a patient’s age, kidney and liver function, how often lamotrigine is taken, and other medications that may interact with lamotrigine. When taken by itself, the half-life of lamotrigine is roughly 25 hours, and it takes five half-lives to eliminate most drugs. So, while the levels of lamotrigine may not be high enough to have noticeable effects, lamotrigine can remain in your system longer than five days after a dose.
When taken with valproate, the half-life of lamotrigine increases to 70 hours. This would increase the time it takes to fully eliminate it from the body to roughly two weeks. Other antiepileptic drugs such as carbamazepine or phenytoin can reduce the half-life of lamotrigine to fourteen hours. In this case, the time to eliminate lamotrigine would be approximately three days.
What happens if I miss a dose of Lamictal?
If you miss a dose of lamotrigine, take the missed dose as soon as you can, but skip the missed dose if it is almost time for your next dose. If you take lamotrigine one daily, and it is less than 12 hours until your next dose, skip the missed dose and take the next dose at the usual time. If you take lamotrigine twice daily, and it is less than eight hours before the next dose is due, skip the missed dose and take your next dose at the usual time.
Do not take two doses at one time. Always remember to get your prescription refilled before you run out of medicine completely. If you miss your doses for more than five days in a row, make sure you tell your doctor. You will need to restart your dosing regimen at a low dose and gradually increase back to your normal dose.
How do I stop taking Lamictal?
It is important to follow your doctor’s instructions about how to take lamotrigine. Do not stop taking lamotrigine unless your doctor tells you to do so. Suddenly stopping lamotrigine can cause withdrawal symptoms, including moodiness, irritability, depression, lethargy, headaches, suicidal thoughts (suicidal ideation), and seizures (in those who are using lamotrigine for epilepsy). Withdrawal symptoms may occur as early as twelve hours after stopping lamotrigine abruptly. The prescribing information recommends titration (gradually lowering the dose) over at least two weeks before discontinuing completely.
Can you overdose on Lamictal?
Taking too much lamotrigine can cause serious and life-threatening adverse effects. Commonly described toxic effects include seizures, movement disorders, reduced consciousness, and cardiovascular symptoms. Call poison control at 1-800-222-1222 if you have taken more than your prescribed dose of lamotrigine and are experiencing rapid, uncontrollable eye movements (nystagmus), increased muscular activity, tremors, poor balance or coordination (ataxia), a noticeable change in heart rate or heart rhythm, or you are feeling faint. Call 911 if you have experienced a seizure, or if you are a witness to someone who has stopped breathing, collapsed, or has had a seizure.
What interacts with Lamictal?
Valproic acid can increase the blood levels of lamotrigine and requires the dose of lamotrigine to be reduced to avoid serious side effects. A serious rash that may be life-threatening—known as Stevens-Johnson Syndrome (SJS) or toxic epidermal necrolysis (TEN)—can occur if the dose of lamotrigine is not adjusted to account for use of valproic acid. This interaction applies to similar formulations of valproic acid, such as Depakote (divalproex sodium) and Depacon (sodium valproate). The risk for SJS is increased when beginning treatment at a high starting dose.
Other medications may reduce the levels of lamotrigine, resulting in reduced efficacy. Examples include carbamazepine, phenytoin, phenobarbital, primidone, rifampin, lopinavir/ritonavir, atazanavir, ritonavir, hormonal contraceptives (estrogen-containing oral or non-oral contraceptives), or estrogen-containing hormone replacement therapies.
Some medications should not be used with lamotrigine because they have similar effects on the central nervous system which become compounded when used with lamotrigine. Examples include buprenorphine and ketamine.
Finally, some drugs should not be used in patients who are taking lamotrigine for seizure control. This is due to their ability to alter seizure control when combined with lamotrigine. Such medications include bupropion, dalfampridine, and metoclopramide.
This is not a comprehensive list of all drugs that could interact with lamotrigine. For medical advice about drug interactions, it is best to consult a doctor or pharmacist and provide a full list of current medications.
What happens when you mix Lamictal and alcohol?
There are no warnings from the manufacturer prohibiting alcohol consumption while taking Lamictal (lamotrigine). However, there are plenty of reasons why alcohol should be avoided in people taking this medicine. The National Institute on Alcohol Abuse and Alcoholism states that alcohol should not be mixed with any anticonvulsant, anxiety medication, or mood stabilizers due to increased drowsiness and dizziness, and increased risk for common side effects. In addition to Lamictal (lamotrigine), these drugs include:
Ativan (lorazepam)
Buspar (buspirone)
Dilantin (phenytoin)
Keppra (levetiracetam)
Klonopin (clonazepam)
Librium (chlordiazepoxide)
Lyrica (pregabalin)
Neurontin (gabapentin)
Paxil (paroxetine)
Phenobarbital
Tegretol (carbamazepine)
Topamax (topiramate)
Trileptal (oxcarbazepine)
Depakote (valproate/valproic acid)
Lithobid (lithium)
Valium (diazepam)
Xanax (alprazolam)
Alcohol can work against antiepileptic drugs by increasing the risk of seizures. Alcohol also worsens many symptoms of bipolar disorder, which in turn can lead to a vicious cycle of alcohol misuse and dependence among those who suffer from this mental disorder. Finally, since lamotrigine is sometimes used to prevent migraines, it should be noted that alcohol can trigger and worsen migraine attacks.
Is it safe to take Lamictal during pregnancy?
Lamotrigine may be taken by pregnant women if a physician determines that the benefit of treatment justifies the potential risk to the fetus. Based on limited human data, there is a possible risk of birth defects such as cleft lip or cleft palate, however, the data conflicts with more recent studies showing no increased risk of birth defects. The risk of uncontrolled seizures during pregnancy must also be considered in the decision whether to use lamotrigine during pregnancy. Monotherapy is generally preferable to using multiple antiepileptic drugs during pregnancy and the lowest effective dose should be used for the shortest duration needed. Folic acid supplementation during the first trimester may offset the risk of a specific birth defect of the neural tube such as spina bifida. In summary, lamotrigine used in combination with folic acid has a relatively favorable safety profile compared to most antiepileptic drugs or mood stabilizers such as valproic acid or topiramate.
The benefits of using lamotrigine for seizure disorder outweigh the risks of fetal harm when taken during lactation (breastfeeding). Although the amount of lamotrigine passed through breast milk is high, the risk of infant harm is low, with possible effects including central nervous system depression, apnea, rash, and poor weight gain.
Related resources for Lamictal dosages:
Acute and persistent withdrawal syndromes following discontinuation of psychotropic medications
Antiepileptic drug safety in pregnancy: Possible dangers for the pregnant woman and her fetus,
Evidence-based guideline update: Pharmacologic treatment for episodic migraine prevention in adults
Lamotrigine during pregnancy does not increase newborn birth defects
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