lamotrigine at a glance
Medicine class
Antiseizure treatment and mood stabiliser
Main uses
Epileptic seizures and prevention of depressive episodes in bipolar I disorder
Food
May be taken with or without food
Important safety point
Any new rash needs prompt medical assessment
What is lamotrigine used for?
Selected UK products are licensed for:
Epilepsy in adults and adolescents, alone or with other treatments, including focal and generalised seizures and seizures associated with Lennox–Gastaut syndrome.
Epilepsy in children aged 2 to 12 years as additional treatment for focal and generalised seizures, including Lennox–Gastaut syndrome, and alone for typical absence seizures.
Prevention of depressive episodes in adults with bipolar I disorder who mainly experience depression. It is not licensed to treat an acute manic or depressive episode.
How does lamotrigine work?
Lamotrigine blocks voltage-gated sodium channels, reducing repeated nerve-cell firing and release of glutamate, an excitatory brain chemical involved in seizures. Its precise mood-stabilising mechanism in bipolar disorder is not established.
lamotrigine preparations and strengths
Dispersible tablet
Route: Oral
Strengths: 25 mg, 100 mg
Oral suspension
Route: Oral
Strengths: 10 mg/mL
Tablet
Route: Oral
Strengths: 25 mg, 50 mg, 100 mg, 200 mg
How to take lamotrigine
Follow the instructions for the formulation supplied and take it consistently. Do not stop or restart lamotrigine without discussing this with the prescriber.
Conventional tablets should be swallowed whole with water and not chewed or crushed.
Chewable/dispersible tablets may be chewed, swallowed whole with water, or dispersed in enough water to cover the tablet. Do not administer part of the resulting mixture.
Shake the oral suspension well before use and measure it with the supplied oral syringe or cup. The selected suspension must not be mixed with other medicines or given through a feeding tube.
lamotrigine side effects
Common or expected effects
- Headache
- Dizziness or sleepiness
- Nausea, vomiting or diarrhoea
- Tremor
- Tiredness or sleep disturbance
- Irritability or agitation
- Dry mouth
- Skin rash
Get urgent medical advice
- Blistering, peeling or painful rash; mouth sores; or rash with fever or swollen glands
- Facial or throat swelling, wheezing or difficulty breathing
- Yellow skin or eyes, severe itching or unusual tiredness suggesting liver injury
- Unexpected bruising, bleeding, breathlessness or marked weakness suggesting a blood disorder
- Persistent fever with rash, swollen glands, neurological symptoms or easy bruising
- Severe headache with stiff neck, light sensitivity, fever or vomiting
- New or worsening thoughts of self-harm
lamotrigine in pregnancy
Lamotrigine can be used during pregnancy when recommended by a specialist. Available evidence is generally reassuring, but epilepsy or bipolar treatment should be reviewed when pregnancy is planned or confirmed; do not stop it suddenly. A clinician may recommend folic acid and clinical and blood-level monitoring because lamotrigine levels can fall during pregnancy and rise after birth.
lamotrigine while breastfeeding
Lamotrigine passes into breast milk and can sometimes produce clinically relevant levels in the infant. Breastfeeding may be possible after an individual benefit–risk discussion; monitor the baby for rash, unusual sleepiness, feeding difficulty or poor weight gain and seek advice if these occur.
lamotrigine interactions
Important interactions can substantially alter lamotrigine exposure or treatment response.
Valproate medicines
They slow lamotrigine metabolism, increasing exposure and the risk of adverse effects, including serious rash.
Carbamazepine, phenytoin, phenobarbital or primidone
These medicines accelerate lamotrigine metabolism and can lower its concentration; carbamazepine-related dizziness, poor coordination or visual disturbance may also become more apparent.
Oestrogen-containing hormonal contraception
It can lower lamotrigine levels, while levels may rise during a hormone-free interval or after stopping. Discuss contraceptive changes and breakthrough bleeding with the prescriber.
Common questions about lamotrigine
Answers are fully visible for fast scanning and source review.
What should I do if lamotrigine causes a rash?
Get prompt medical advice for any new rash. Seek urgent help if it is blistering, peeling, painful or accompanied by fever, mouth sores, facial swelling or swollen glands.
Can lamotrigine be taken with food?
Yes. It may be taken with or without food.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.