Large Description (basic): 

Lamictal (lah-MIK-tal) is the brand name used in the United States, Canada, the UK, Australia, and other countries for the seizure medicine lamotrigine (lah-MO-trih-jeen). Lamictal is available in generic form as lamotrigine.

Used to treat: 

Forms (basic): 

Lamictal is sold in the United States by GlaxoSmithKline. The name or appearance may be different in various countries but usually the dose (measured in milligrams, abbreviated "mg") will be the same. These descriptions apply to the U.S. versions:

How to take and store Lamotrigine?

Follow the doctor's directions. Call if you have any questions. Ask the doctor what to do if you forget a dose. The way the medicine is taken depends, of course, on what form the doctor has prescribed.

Swallow regular Lamictal tablets whole. Chewing them may leave a bitter taste. All the tablets of this type are shaped like a shield and marked with the name "LAMICTAL" and the number of milligrams in the dose.

If you have chewable dispersible tablets, you can swallow them whole, chew them, or mix them in a liquid like water or diluted fruit juice. If you chew these tablets, you probably will want to drink a little water or diluted juice to help you swallow. To mix them in a liquid, add the tablets to a small amount of the water or juice (1 teaspoon, or enough to cover the tablets) in a glass or spoon. Wait about 1 minute, until the tablets have completely broken up. Then carefully stir the liquid and drink it all immediately.

It's OK to take Lamictal either with food or without food, but it's best to be consistent from day to day. People who usually take Lamictal with food should try to do that all the time, because it affects the way the medicine is used by the body.

As the doctor increases the amount of Lamictal that you take, you may be given a different kind of tablet than the ones you've been taking. For example, if you've been taking 100-mg tablets and the new prescription is for 150-mg tablets, be careful to take the correct number. Don't automatically continue to take the same number of pills as before.

Take only the number of tablets that your doctor tells you to take. If you think you've taken one or two extra tablets, call the doctor for advice. For a larger overdose, call your local poison control center or emergency room right away.

Store Lamictal tablets at room temperature away from heat, light, and moisture. Don't keep them in the bathroom if it's damp there. And of course keep them where children can't get at them.

What if I forget?

In general, if you forget a dose, take it as soon as you remember. If it is almost time for the next dose, delay that dose for a few hours, instead of taking two doses very close together. Then go back to the regular schedule. If you usually take Lamictal only once day, it might be a good idea to wait about 12 hours before taking the next dose. Then you can go back to a 24-hour schedule the next day. If you're not sure about what to do, call the doctor's office for more advice.

If you forget doses often, it may be a good idea to get a special pillbox or watch with an alarm to remind you.

Taking the right amount of seizure medicine on time every single day is the most important step in preventing seizures!

How does Lamotrigine effect the brain?

Brain cells need to work (fire) at a certain rate to function normally. During a seizure, brain cells are forced to work much more rapidly than normal. Lamictal helps prevent brain cells from working as fast as a seizure requires them to. In this way, seizures can be stopped when they are just beginning.

How does the body digest Lamotrigine?

After medicine is swallowed, it must be absorbed into the blood so it can move throughout the body. The process of absorbing, digesting, and excreting a medicine or food is called metabolism. The way the body metabolizes a particular medicine affects how often it must be taken. It also determines whether it will interact with other medicines or be affected by conditions such as liver disease.

Like many other medicines, Lamictal is broken down (digested) in the liver. People with liver disease must be cautious about taking it. But even if your liver is fine, things can get complicated if you also take other medicines that are digested in the liver. How well each medicine works and how quickly it leaves the body may be changed.

All types of Lamictal tablets are quickly and completely absorbed. The rate at which Lamictal is digested can vary a great deal, however, depending on whether other seizure medicines are also taken:

  • People who also take Depakote or other medicines of that type need to take much less Lamictal because their bodies process it more slowly than usual.
  • People who take some other seizure medicines need larger doses of Lamictal because their bodies process it quickly. Medicines with this effect include:
    • Tegretol, Carbatrol (carbamazepine)
    • Dilantin, Phenytek (phenytoin)
    • phenobarbital
    • Mysoline (primidone)

This is why the doctor needs to know about everything you take—not just prescription medicines but even things like vitamins, herbs, and aspirin! These things can affect how much Lamictal is prescribed.

How well does the Lamotrigine work?

Lamictal (lamotrigine) is approved by government agencies in most countries to be used as an add-on medicine for adults whose partial seizures are not well controlled by another seizure medicine. Doctors have studied groups of people who have used Lamictal in this way, comparing them with other patients who were given pills with no medicine in them (called a placebo). The doctors counted how many people had their seizures reduced by at least half. They found that 16% to 20% more people who took Lamictal met that standard than ones who took the placebo. The people who took Lamictal had more trouble with side effects, but the side effects were generally minor and often went away without stopping the medicine.

Lamictal is used to treat several different types of seizures. In one study, Lamictal was given as an add-on medicine for patients with the pattern of seizures called Lennox-Gastaut syndrome. Compared to patients who were given a placebo, 23% more patients who took Lamictal had the number of their tonic-clonic seizures cut at least in half. Many of the other patients who took the Lamictal had little improvement, however.

No single combination of seizure medicines is perfect for everyone. Sometimes a series of combinations must be tried before finding what is best for the individual. Many other seizure medicines affect the way the body uses Lamictal, so the amount of each medicine that the person takes may need to be adjusted.

Some other studies have compared Lamictal with other seizure medicines when they are used alone, to see which medicine is best for people who have just begun treatment for epilepsy. On average, the results were about the same for Lamictal as for some other seizure medicines that are often used, but the patients in these studies who took Lamictal had fewer problems with side effects.

What are the most common side effects of Lamotrigine?

Most people who take Lamictal don't have too much trouble with side effects. The most common complaints include:

  • dizziness
  • upset stomach
  • headache
  • unsteadiness
  • double vision
  • rash

Most of these problems are mild to moderate.

If you notice any of these problems, call the doctor. Sometimes the doctor can help by changing the amount of Lamictal taken or how you take it. No one should stop taking Lamictal or change the amount they take without a doctor's advice.

On the positive side, fewer people say they feel tired when they take Lamictal than with most other seizure medicines. In fact, for many people it's slightly stimulating. This is often a welcome side effect unless it keeps them awake at night.

People who have just started taking Lamictal (or who have just started taking a larger amount) should be careful during activities that might be dangerous, until they know whether they are having any side effects.

Allergic reactions
About 10% of people who take Lamictal experience a rash. Almost none of these rashes are serious. They most often occur in the first 6 weeks of treatment, so during this time, try to be aware of any skin problems and tell the doctor or nurse right away if you see a red rash, to be sure that it's not the beginning of a serious problem. It's often necessary to switch to a different seizure medicine.

Long-term side effects 
So far, we don't know about any long-term side effects of Lamictal.

What are the most serious side effects of Lamotrigine?

Only a tiny number of people who take Lamictal have dangerous reactions to it. Most have no side effects, or perhaps mild ones that go away by themselves or can be easily treated.

It's important to recognize the most serious side effects, however. Here's a list of warning signs that may be the start of a serious problem. If you notice any of these signs, call your doctor right away:

  • Rash or hives
  • Fever and swollen lymph glands
  • Painful sores in the mouth or around the eyes
  • Swelling of lips or tongue

A serious rash while taking Lamictal has been reported in about 3 in 1000 adults and 1 in 100 children. Be sure to follow the doctor's instructions about how much Lamictal to take, because starting with a low dose and increasing it gradually will reduce the risk of these reactions. If you see a rash, talk to the doctor about whether to stop taking Lamictal. Do not stop taking Lamictal or any other seizure medicine unless your doctor says so.

On July 10, 2008, an advisory panel was convened by the Food and Drug Administration (FDA) to review data that the FDA had previously collected from drug studies showing an association between many of the antiepileptic drugs (AEDs) and suicidal ideation and behavior, which together are called suicidality. According to the FDA’s Alert, among the patients with epilepsy in these drug studies, 1 out of 1000 people taking the placebo (inactive substance) showed suicidality compared to approximately 3.5 out of 1000 people who took an AED. The FDA advisory panel voted to accept the FDA's data at its meeting on July 10. The FDA has provided the following information for patients, family members, and caregivers at http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/ucm100192.htm.

  • Taking antiepileptic medicines may increase the risk of having suicidal thoughts or actions;
  • Do not make any changes to the medication regimen without first talking with the responsible healthcare professional;
  • Pay close attention to any day-to-day changes in mood, behavior and actions. These changes can happen very quickly so it is important to be mindful of any sudden differences.
  • Be aware of common warning signs that might be a signal for risk of suicide. Some of these are:
    • Talking or thinking about wanting to hurt yourself or end your life
    • Withdrawing from friends and family
    • Becoming depressed or having your depression get worse
    • Becoming preoccupied with death and dying
    • Giving away prized possessions

We again urge patients and families to contact their doctor before stopping an epilepsy medication because this may possibly lead to seizures and worsening of mood.

What else is Lamotrigine used for?

The U.S. Food and Drug Administration (FDA) has approved Lamictal as an additional treatment for bipolar disorder, a mental illness.

It is also legal to prescribe medicines for "off-label uses" even though the FDA has not formally approved such use. Lamictal is sometimes prescribed "off-label" for certain types of pain.

Who should not take Lamotrigine?

The only people who definitely should not take Lamictal (lamotrigine) are those who are allergic to it.

People with liver disease and those who must take certain other types of medicines may need to be more cautious than others about taking Lamictal. Most of them can take it successfully, however, if they work with the doctor to determine the correct amount to take. That is why it is so important to make sure the doctor knows about any liver disease and about every kind of medicine in use.

Can Lamotrigine be taken with other medicines?

Sometimes one kind of medicine changes the way another kind of medicine works in the body. This is true not only for prescription medicines, but also for medicines you just pick up off the shelf at the store. It’s also true for herbal products, vitamins, a few kinds of food—sometimes even cigarettes!

Any time a doctor suggests a new prescription, be sure to talk about what other medicines you are already using. If two kinds of medicine affect each other, the doctor may want to prescribe something else or change the amount to be taken.

How does Lamictal affect other medicines?
Lamictal has no effect on other seizure medicines. And unlike some other seizure medicines, it does not reduce the effectiveness of birth control pills.

How does birth control affect Lamictal?
Although Lamictal does not reduce the effectiveness of birth control pills, there is a possiblity that birth control pills can lower the amount of lamotrigine levels in your blood, thus increasing the likelihood of unexpected seizures. If you start or stop taking an oral contraceptive, and are currently taking Lamictal (lamotrigine)--please notify your doctor

How do other seizure medicines affect Lamictal?
Some other seizure medicines do affect the level of Lamictal in the body, either raising it or lowering it. Many of these interactions vary from person to person, however. Some may even vary from time to time for the same person. Make sure that your doctor is aware of all the seizure medicines you're using.

One common seizure medicine, Depakote (and others closely related to it), will make the level of Lamictal in the body much higher. People who take both Depakote and Lamictal need to take smaller amounts of Lamictal.

On the other hand, some other seizure medicines reduce the amount of Lamictal in the body, so more must be taken. (This is not true if Depakote is also being used.) The seizure medicines with this effect are:

  • Tegretol or Carbatrol (carbamazepine)
  • Dilantin or Phenytek (phenytoin)
  • phenobarbital
  • Mysoline (primidone)
What are the effects of Lamotrigine on Children?

The FDA has approved Lamictal for some seizures in children as young as 2 years of age. Research suggests that it is effective for many seizure types, including Lennox-Gastaut syndrome.

Many children take Depakote or other valproate medicines (Depakene, valproic acid). These medicines make Lamictal stay in the body much longer. To keep from having too much Lamictal in their body (which would probably cause unwanted side effects), these children must take very small doses of it. Other children may take up to 5 times as much!

Doctors figure out how much medicine to give to young children based mostly on their weight. Children ages 2 to 12 who are also taking Depakote will probably end up taking 1 to 5 milligrams (mg) per day of Lamictal for every kilogram (kg, about 2.2 pounds) of their body weight. For example, a 55-pound child taking 3 mg per kg would be given 75 mg per day. (Of course, they will start by taking much less.) Children who don't take Depakote generally take between 5 and 15 mg per kg per day. The pills are usually given twice a day.

The amount of Lamictal taken by children over 12 is more like the adult dose, which also depends on whether the person is taking Depakote.

If a woman takes Lamotrigine during pregnancy will it hurt the baby?

Recently, the North American AED Pregnancy Registry, located at Massachusetts General Hospital in Boston, Massachusetts, found that infants who are exposed to lamotrigine as monotherapy during pregnancy (lamotrigine was used as the only AED by the mother) have a much higher risk of having an oral cleft problem, than infants born to women in a comparison group and who were not exposed to lamotrigine during pregnancy. Oral cleft problems are birth defects that may involve the lip (cleft lip), the palate (cleft palate), or both. During pregnancy, the normal openings between the upper lip and the nose (seen with cleft lip) or between the roof or back of the mouth and the nose (seen in cleft palate) may not close properly. These problems can often be seen with ultrasound testing and can usually be corrected after birth with surgery.

In this study, of 564 women who received lamotrigine alone, 5 instances of isolated cleft lip or palate (not seen as part of any specific syndrome) were seen in the babies. This data gives a prevalence rate of 8.9 per 1000, which means that oral cleft problems may occur in 8.9 of 1000 women treated with lamotrigine monotherapy. This number is 24 times higher than the risk of oral cleft problems seen in babies from the comparison group used in the study.

This information should be interpreted with caution and further analysis is underway. Women taking lamotrigine should talk to their doctors if they become pregnant or are considering pregnancy, and discuss the risks and benefits of taking lamotrigine during pregnancy. The manufacturer of Lamictal, the brand name version of lamotrigine, has stated that "Lamictal should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus".

Women who are interested in participating in pregnancy registries , may enroll themselves in the North American AED Pregnancy Registry by calling 1-888-233-2334.

Taking medications during pregnancy is often a concern for women who are pregnant. Most medications carry some risk, but the extent of risk is often unknown. The risks of antiepileptic drugs to babies born to women taking AEDs during pregnancy  is a source of ongoing research around the world.

In the United States, the Food and Drug Administration (FDA) assigns each medication to a Pregnancy Category according to whether it has been proven to be harmful in pregnancy. Lamictal is listed in Pregnancy Category C. This indicates that caution is advised, but the benefits of the medicine may outweigh the potential risks. Studies in animals have shown some harm to the baby, but there haven't been any good studies of results in women. There is no indication yet that Lamictal causes serious birth defects.

The risk of birth defects is higher for women who take more than one seizure medicine and for women with a family history of birth defects.

All women who are capable of becoming pregnant should take at least 0.4 mg (400 mcg) of the vitamin called folic acid every day because it helps to prevent one type of birth defect. (The most well-known of these is spina bifida, in which the spinal cord is not completely enclosed.) Women at high risk, such as those with a history of this kind of defect in a previous pregnancy, should take 4000 mcg (4 mg) daily, beginning before they become pregnant.

About 20% to 35% of women have seizures more often during pregnancy because of changes in hormones or changes in how their seizure medicine is handled by the body. This appears to be particularly true for Lamictal. It is helpful for the doctor to check the levels of medicine in the blood regularly during pregnancy so that the dosage can be adjusted if necessary.

Talk to the doctor if about your options if you're interested in breast-feeding the baby. The baby will get some Lamictal through the milk, and its possible effects are unknown. For this reason, breast-feeding while taking Lamictal is not recommended.

What are the effects of Lamotrigine on Seniors

Lamictal is commonly prescribed for epilepsy in people over 65. It's important for the doctor to prescribe a very low dose at the beginning and increase it more slowly than for a younger person.

Seniors tend to be more sensitive than younger adults to medicines and their side effects, and may have more trouble as a result. For instance, even before they start taking Lamictal, some seniors have problems with unsteadiness or dizziness. These are common side effects of this medicine. If the Lamictal makes them worse, the person could be in real danger from falls or other accidents.

Starting at a very low dose of Lamictal and being very cautious about any increases should help to control side effects. It’s especially important for seniors to keep the doctor informed about any changes that they notice.

What are the dose ranges for Lamotrigine?

The best amount is the amount that completely controls seizures without causing troublesome side effects. It depends on many factors, which are different for every individual. Follow the doctor's directions. Call if you have any questions.

No one should stop taking Lamictal or change the amount they take without talking to the doctor first. Stopping any seizure medicine all at once can cause a problem that may be life-threatening.

Don’t use more than the doctor prescribes. If a little extra (such as one or two extra tablets) is taken by accident, call the doctor for advice. For a larger overdose, call a poison control center or emergency room right away unless you have other specific directions from your doctor.

To avoid unwanted side effects, the doctor will prescribe a low dose to start and increase it gradually until seizures are controlled. The amount the doctor will prescribe will depend on what other seizure medicines are taken. Most people need to take Lamictal twice a day, but some need to take it only once a day.

Read the package insert of Lamotrigine

In the United States, companies that manufacture medicines are required to publish certain kinds of information about each product. This document is commonly known as a “package insert” because it is usually included with each package of the medicine.

You can also read these documents (also called "prescribing information") online. The U.S. package insert for Lamictal (lamotrigine) is found at:

Some of the information may differ in other countries.

To learn how to read and understand a package insert, see How to read a package insert.

Large Description (adv): 

Lamictal is the brand name used in the United States, Canada, the UK, Australia, and other countries for lamotrigine.

Lamictal was approved by the FDA in 1994 for the treatment of partial seizures and secondarily generalized seizures in adults, and in 1998 as an add-on treatment for generalized seizures associated with Lennox-Gastaut syndrome. More recently, Lamictal was approved as monotherapy.

Indications (adv): 

The U.S. Food and Drug Administration (FDA) has approved lamotrigine as adjunctive therapy for both adults and children aged 2 years and older for

  • simple and complex partial seizures
  • generalized seizures of Lennox-Gastaut syndrome (LGS)
  • primary generalized tonic-clonic seizures

It is also FDA-approved as monotherapy in adults for the treatment of simple and complex partial seizures after conversion from valproate or a single enzyme-inducing antiepileptic drug (carbamazepine, phenytoin, primidone, or phenobarbital).

Forms (adv): 

Lamictal is sold in the United States by GlaxoSmithKline. These descriptions apply to the U.S. versions:

How to take and store Lamotrigine?

Lamictal can be taken with food or without food, but advise your patients to be consistent from day to day.

Regular Lamictal tablets should be swallowed whole because chewing them may leave a bitter taste.

Lamictal "Chewable Dispersible Tablets" can be swallowed whole, chewed, or mixed in water or diluted fruit juice and swallowed immediately.

All Lamictal tablets should be stored at room temperature, away from heat, light and moisture. Remind patients also to keep them safe from children.

Missed Doses

In general, tell patients that if they forget a dose, they should take it as soon as they remember. If it is almost time for the next dose, they should delay that dose for a few hours, instead of taking two doses very close together.

Patients who often forget doses may benefit from using a special pillbox or watch with an alarm.

Mechanisms of actions of Lamotrigine

The mechanism of action of Lamictal is related to inactivation of voltage-dependent sodium channels. However, this would not account for its apparent action against absence and myoclonic seizures.

Lamictal may selectively influence neurons that synthesize glutamate and aspartate, since it diminishes the release of these excitatory neurotransmitters through its effect on sodium channels.

Clinical Pharmacology of Lamotrigine

Absorption
Lamictal is quickly and totally absorbed when given orally, and plasma concentrations have an apparent linear relationship to dose.

Distribution and metabolism
The drug is approximately 55% bound to plasma proteins. The liver metabolizes Lamictal to inactive glucuronide conjugates that are excreted in the urine.

The half-life of Lamictal taken alone is about 25 hours, but it rises to 70 hours in patients also taking valproate. In patients also taking hepatic enzyme–inducing AEDs, the half-life of Lamictal drops to 14 hours.

Steady state
Steady state is reached after 3 to 15 days, depending on whether Lamictal is taken with enzyme-inducing AEDs, valproate, or neither.

Efficacy of Lamotrigine

Randomized, controlled studies add-on studies of Lamictal in patients with refractory partial seizures found that Lamictal reduces seizure frequency by at least half in 16% to 20% more patients than add-on placebo (Messenheimer et al. 1994). Side effects were more troublesome than with the placebo, but they were generally minor and often went away without stopping the medication.

Lamictal is also used to treat absence, myoclonic, and tonic-clonic seizures. It is effective against some seizure types in patients with Lennox-Gastaut syndrome and other forms of symptomatic generalized epilepsy. In one study using Lamictal as add-on therapy for patients with Lennox-Gastaut syndrome, 23% more patients who took Lamictal (compared to a placebo) had the number of their tonic-clonic seizures cut at least in half (Motte et al. 1997). Nearly half of the patients who took the Lamictal had less than a 25% decrease in these seizures, however.

Studies have also looked at the effectiveness of Lamictal used alone. In one study (Brodie et al. 1995), patients with newly diagnosed epilepsy were treated with either Lamictal or carbamazepine (Tegretol, Carbatrol). A similar study (Steiner et al. 1999) compared Lamictal to phenytoin (Dilantin, Phenytek). The patients in these studies had partial seizures with or without secondary generalization, or they had primary generalized tonic-clonic seizures. In each study, the effect on the frequency of each seizure type was almost the same for both medications, but the patients taking Lamictal had fewer problems with side effects.

Common side effects of Lamotrigine

Dose-related side effects
The common dose-related side effects of Lamictal are neurotoxic and include:

  • insomnia
  • drowsiness
  • dizziness
  • headache
  • somnolence
  • diplopia
  • ataxia

Increased alertness may be experienced as a side effect that is beneficial to the patient. Neurotoxic side effects are more likely if Lamictal is taken at the same time as carbamazepine or oxcarbazepine. This effect can be reduced by staggering the doses by 1-2 hours.

Lamictal has no known long-term side effects.

Idiosyncratic reactions
The primary systemic side effects of Lamictal are rash and nausea. A benign rash may develop in up to 10% of patients during the initial one to two months of therapy.

Serious Side effects of Lamotrigine

In some patients, rash progresses to a systemic illness with fever, arthralgia, myalgia, lymphadenopathy, eosinophilia, and malaise. Erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrolysis occur rarely. Based upon clinical trials and post-marketing reports, the risk of severe dermatologic reaction is 0.3% in adults and approximately 1% in children 16 years and younger.

The risk factors for severe dermatologic reactions with Lamictal include:

  • younger age (children more than adults)
  • co-medication with valproate
  • a rapid rate of Lamictal titration
  • high Lamictal starting dose

Any rash should be evaluated promptly. It is generally recommended that Lamictal be discontinued at the first sign of rash, unless the rash is clearly not drug-related.

On July 10, 2008, an advisory panel was convened by the Food and Drug Administration (FDA) to review data that the FDA had previously collected from drug studies showing an association between many of the antiepileptic drugs (AEDs) and suicidal ideation and behavior, which together are called suicidality. According to the FDA’s Alert, among the patients with epilepsy in these drug studies, 1 out of 1000 people taking the placebo (inactive substance) showed suicidality compared to approximately 3.5 out of 1000 people who took an AED. The FDA advisory panel voted to accept the FDA's data at its meeting on July 10. The FDA has provided the following information for patients, family members, and caregivers at http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/ucm100192.htm.

  • Taking antiepileptic medicines may increase the risk of having suicidal thoughts or actions;
  • Do not make any changes to the medication regimen without first talking with the responsible healthcare professional;
  • Pay close attention to any day-to-day changes in mood, behavior and actions. These changes can happen very quickly so it is important to be mindful of any sudden differences.
  • Be aware of common warning signs that might be a signal for risk of suicide. Some of these are:
    • Talking or thinking about wanting to hurt yourself or end your life
    • Withdrawing from friends and family
    • Becoming depressed or having your depression get worse
    • Becoming preoccupied with death and dying
    • Giving away prized possessions

We again urge patients and families to contact their doctor before stopping an epilepsy medication because this may possibly lead to seizures and worsening of mood.

Other Uses of Lamotrigine

Lamictal is approved as maintenance therapy for bipolar disorder. It is used off-label for neuropathic pain and trigeminal neuralgia.

Lamotrigine Contraindications

Patients who are allergic to lamotrigine should not take Lamictal.

Caution should be exercised when prescribing Lamictal for patients who have liver disease and for those taking valproate, because of the increased risk of serious rash.

Lamotrigine Interactions with other medications

Serum concentrations of Lamictal are not influenced by interactions with non-AEDs, but are markedly increased by an interaction with valproate, which inhibits glucuronidation, the main metabolic pathway of Lamictal. Consequently, the half-life of Lamictal varies according to concomitant therapy. If the patient is taking hepatic enzyme–inducing AEDs, the half-life is 14 hours, whereas if the patient is taking valproate (e.g., Depakote), the half-life is approximately 70 hours. As a result, if valproate is added to Lamictal, the Lamictal dose will probably need to be reduced.

Another consequence of this interaction is that if hepatic enzyme–inducing drugs are withdrawn, the serum concentration of Lamictal will rise. Withdrawing valproate, on the other hand, will lower the Lamictal concentration. Similarly, if oral contraceptives are stopped for 7 days each month, Lamictal levels will increase during that week. Lamictal levels will fall when the oral contraceptive is restarted.

Lamotrigine does not alter the hepatic metabolism of other drugs, including other AEDs.

AED Interaction Sheets: 
Seizure drugs are often affected by drug-drug interactions. Print these informative sheets for practical help.

Lamotrigine effects on Children

The FDA has approved Lamictal for use as adjunctive therapy for partial seizures in children as young as 2 years. It is also approved as adjunctive therapy for generalized seizures in children with Lennox-Gastaut syndrome.

A main concern with Lamictal and its use for children is the interaction with valproate, because of the increased risk of severe rash. Lamictal should always be introduced gradually to prevent toxicity and the development of a rash. Other than rash, the most common side effects include dizziness, sleepiness, double vision, and sometimes upset stomach.

Dosage for Lamictal depends on the age of the child and whether the child is also taking valproate. For children aged 2 to 12 years who are also taking valproate, the starting dose is 0.15 mg/kg per day in one or two divided doses, and the usual maintenance dose is 1 to 5 mg/kg per day. Without valproate, children aged 2 to 12 years start at 0.6 mg/kg per day and the usual maintenance dose is 5 to 15 mg/kg per day.

For children over 12 years of age who are taking valproate, the starting dose is 25 mg every other day and the usual maintenance dose is 100 to 400 mg per day (in one or two divided doses). Children over 12 who don't take valproate usually start at 50 mg per day and work up to 300 to 500 mg per day.

Lamotrigine and Pregnancy

Emerging data from a pregnancy registry suggest an association between LAMICTAL ® (lamotrigine) and an increased risk of non-syndromic oral clefts

The U.S. Food and Drug Administration (FDA) lists Lamictal in Pregnancy Category C. This indicates that caution is advised, but the benefits of the medication may outweigh the potential risks. So far there is no indication that Lamictal causes serious birth defects, but there have been no well-controlled studies in women, and studies in animals have shown some harm to the fetus.

The risk of birth defects is higher for women who take more than one AED and for women with a family history of birth defects.

Women who are capable of becoming pregnant should take at least 400 mcg (0.4 mg) of folic acid (folate) daily to help prevent a type of birth defect called a neural tube defect. (The best-known of these is spina bifida, in which the spinal cord is not completely enclosed.) Women at high risk, such as those with a history of this kind of defect in a previous pregnancy, should take 4000 mcg (4 mg) daily, beginning before they become pregnant. Whether folic acid is effective in preventing defects has not been proven, however, so the doctor may recommend a check-up using ultrasound during the 18th to 20th week of pregnancy.

About 20% to 35% of women have seizures more often during pregnancy because of changes in hormones or changes in how their seizure medicine is handled by the body. This appears to be particularly true for Lamictal. Therefore, the doctor may recommend checking the level of Lamictal in the blood regularly during pregnancy so that the dosage can be adjusted as needed.

The risks, benefits, and options should be discussed with women taking Lamictal who are interested in breast-feeding. The baby will get some Lamictal through the milk, and its possible effects are unknown. For this reason, breast-feeding while taking Lamictal is not recommended.

Lamotrigine effects on Seniors

Older people metabolize Lamictal more slowly than younger adults and they may be more susceptible to its side effects. Therefore, lower initial doses and caution in titration are advisable.

Lamotrigine Dosing and titration

The appropriate dosages of Lamictal depend on what other AEDs, if any, the patient is taking. If Lamictal is used as monotherapy for young adults, the starting dose is 25 mg a day, increased every two weeks by 25 mg daily as needed, usually to 100-200 mg a day.

For young adults who are taking hepatic enzyme–inducing AEDs, however, Lamictal is usually started at 25 mg twice a day. Every 1-2 weeks, the amount can be increased by 50 mg per day as required (if side effects are not troublesome) to a target dose of 300-500 mg per day. The AEDs that require these higher dosages of Lamictal are:

  • carbamazepine (Tegretol, Tegretol-XR, Carbatrol)
  • phenytoin (Dilantin, Phenytek)
  • phenobarbital)
  • primidone (Mysoline)

For adults taking valproate (Depakote, Depakote ER, valproic acid), the initial dose is 12.5 to 25 mg every other day, with increases of 25 mg per day every two weeks as needed and tolerated, usually to 150-200 mg daily.

Patients over age 65 generally require a lower initial dose and lower target maintenance dose.

Measurements of serum concentrations are useful, particularly if the patient stops or starts enzyme-inducing AEDs or valproate. Therapeutic serum concentrations of lamotrigine have not been established, but generally levels of 5-15 mcg/mL are achieved.

Lamotrigine Package insert

In the United States, companies that manufacture medicines are required to publish certain kinds of information about each product. This document is commonly known as a “package insert” because it is usually included with each package of the medicine.

You can also read these documents (also called "prescribing information") online. The U.S. package insert for Lamictal (lamotrigine) is found at:

Some of the information may differ in other countries.

To learn how to read and understand a package insert, see How to read a package insert.

Lamotrigine References for Professionals

Abstracts of articles relevant to this topic are available through PubMed, a service of the National Library of Medicine.

Here are links to some articles relevant to this subject:

Messenheimer J, Ramsay RE, Willmore LJ, et al. Lamotrigine therapy for partial seizures: a multicenter, placebo-controlled, double-blind, cross-over trial. Epilepsia 1994 Jan-Feb;35(1):113-21. PMID: 8112232.

Motte J, Trevathan E, Arvidsson JF, et al. Lamotrigine for generalized seizures associated with the Lennox-Gastaut syndrome. Lamictal Lennox-Gastaut Study Group. N Engl J Med 1997 Dec 18;337(25):1807-12. PMID: 9400037.

Brodie MJ, Richens A, Yuen AW. Double-blind comparison of lamotrigine and carbamazepine in newly diagnosed epilepsy. UK Lamotrigine/Carbamazepine Monotherapy Trial Group. Lancet 1995 Feb 25;345(8948):476-9. PMID: 7710545.

Steiner TJ, Dellaportas CI, Findley LJ, et al. Lamotrigine monotherapy in newly diagnosed untreated epilepsy: a double-blind comparison with phenytoin. Epilepsia 1999 May;40(5):601-7. PMID: 10386529.

Cramer JA, Ben Menachem E, French J. Review of treatment options for refractory epilepsy: new medications and vagal nerve stimulation. Epilepsy Res 2001 Nov;47(1-2):17-25. PMID: 11673017.