Lamotrigine for Lennox-Gastaut syndrome
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Lamotrigine is an approved oral medication used as an add-on treatment to control seizures in people with Lennox-Gastaut syndrome (LGS).
Seizures are characterized by abnormal electrical activity in the brain. Lamotrigine works mainly by inhibiting certain sodium channels on nerve cells that enable them to fire electrical signals. In doing so, the medication helps prevent the abnormal firing that leads to seizures.
In the U.S., GSK sells lamotrigine under the brand name Lamictal. It can be taken in several forms: as oral tablets to be swallowed, oral tablets to be dissolved into a liquid suspension, and orally disintegrating tablets that dissolve in the mouth. Subvenite and Lamlique are two ready-to-use oral liquid suspensions of lamotrigine. Generic versions of the drug are also available. The medication is also used to treat bipolar disorder.
Therapy snapshot
| Brand name | Lamictal, Subvenite, Lamlique |
| Chemical name | Lamotrigine |
| Usage | Used as an add-on to manage seizures in LGS |
| Administration | Oral tablets, suspension, or orally disintegrating tablets |
Who with LGS can take lamotrigine?
In the U.S., lamotrigine is approved as an adjunctive therapy to manage generalized seizures in people with LGS, ages 2 and older. It is also indicated to be used as an add-on for treating certain seizure types in people with all forms of epilepsy, or as a standalone therapy for people ages 16 and older.
Lamotrigine is also approved for treating LGS in the European Union and Canada.
The medication is contraindicated, or should not be used, by people with a history of immune reactions (hypersensitivity) to the medication or any of its ingredients.
Lamotrigine comes with a boxed warning that it may cause life-threatening serious rashes. The risk may be highest in people who are simultaneously receiving the antiepileptic medication valproate, who exceed the recommended dose of lamotrigine, or who have a certain genetic risk marker. The medication is not recommended for people who have experienced any such rash.
How is lamotrigine administered in LGS?
Lamotrigine comes in a few different formulations, including:
- tablets, to be swallowed whole
- tablets for oral suspension, which can be dissolved in water or fruit juice, swallowed, or chewed
- orally disintegrating tablets that are placed on the tongue, where they dissolve with or without water
- a ready-to-use oral liquid
Dosing in LGS is based on other antiepileptic medications and age. To reduce the risk of rash, lamotrigine is started at a lower dose and gradually increased over the first five weeks. Thereafter, the recommended maintenance dosing is as follows:
- patients ages 2-12: 1 to 15 mg/kg, with increases in children weighing less than 30 kg (about 66 pounds)
- patients older than 12: 100-500 mg daily
The total dose may be taken once daily or split into two divided doses. When stopping treatment, the dose will be tapered slowly over at least two weeks.
Dosing adjustments are needed for most people who are stopping or starting estrogen-containing products, including oral contraceptives, as well as for people with moderate or severe liver problems.
Lamotrigine in LGS clinical trials
The benefits of lamotrigine as an add-on therapy in people with LGS were established in a placebo-controlled trial involving patients ages 3 to 25. Participants received either lamotrigine or a placebo for about four months in addition to other antiepileptic medications. The results showed that:
- the median frequency of all major seizures was significantly reduced with lamotrigine relative to the placebo
- about a third of participants given the medication had at least a 50% reduction in seizure frequency compared with 16% of the placebo group
A number of other studies in adults and children with epilepsy supported lamotrigine’s use as an add-on or standalone therapy for specific seizure types.
Lamotrigine side effects
The most common side effects of the medication’s use in adults with epilepsy are:
- dizziness
- headache
- double or blurred vision
- coordination problems
- nausea
- drowsiness
- stuffy or runny nose
- sore throat
- rash
Additional side effects reported in children were:
- vomiting
- infection
- fever
- accidental injury
- diarrhea
- abdominal pain
- tremor
Life-threatening serious rashes that have occurred with lamotrigine include Stevens-Johnson syndrome and toxic epidermal necrolysis. These occur more often in children and within 2-8 weeks of treatment initiation, but can happen in any person at any time.
Harmless rashes can also occur, and it is not possible to predict which rashes will be serious or life-threatening. Individuals will be carefully monitored, and lamotrigine should be discontinued at the first sign of a rash that could be drug-related. The medication should not be restarted unless the potential benefits outweigh the risks.
Lamotrigine also comes with warnings for other serious adverse events. Patients will be carefully monitored, and if these event occur, lamotrigine may need to be discontinued. These include:
- hemophagocytic lymphohistiocytosis, a life-threatening inflammatory reaction
- fatal or life-threatening hypersensitivity reactions, including multiorgan involvement
- heart rhythm abnormalities
- blood abnormalities, including low blood cell counts
- suicidal thoughts and behaviors
- inflammation of the membranes covering the brain (aseptic meningitis)
Lamotrigine may interact with other medications. As such, individuals should alert their doctors about all other drugs they are using. The name lamotrigine may be confused with other commonly used medications, so patients are advised to inspect their medication to ensure they have received the right prescription.
Antiepileptic medications, including lamotrigine, should not be abruptly discontinued due to the possibility of worsening seizures.
Lennox-Gastaut Syndrome News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.
