Dosage
For epilepsy, the usual dose of lamotrigine is:
- adults and older children (aged 12 years and over) – 100mg to 700mg a day, taken as 1 or 2 doses
- younger children (aged 2 to 11 years) – the dose will vary depending on their weight
For bipolar disorder, the usual dose for adults is:
- between 200mg and 400mg a day, taken as either 1 or 2 doses
Changes to your dose
When you start taking lamotrigine, it's important to increase the dose slowly as this will help reduce or stop side effects.
Once you find a dose that suits you, it'll usually stay the same.
How to take it
You'll usually take lamotrigine once or twice a day. You can take it with or without food.
If you take it twice a day, try to space your doses evenly through the day. For example, take it first thing in the morning and in the evening.
If you're taking standard tablets, swallow them whole with a drink of water. Do not chew them.
If you're taking chewable or dispersible tablets, you can swallow them whole with a drink of water, or chew them or mix them with water or juice to make a drink.
How long to take it for
If you have epilepsy, it's likely that once your condition is under control you'll still need to take lamotrigine for many years.
If you have bipolar disorder, it's likely that you'll take lamotrigine for at least 6 months, but possibly much longer.
Important
Do not stop taking lamotrigine without speaking to your doctor first.
If you forget to take it
If you take lamotrigine once a day and forget your dose, take the missed dose as soon as you remember, unless it's less than 12 hours until your next dose is due. In this case, leave out the missed dose and take your next dose at the usual time.
If you take it twice a day, take the missed dose as soon as you remember, unless it's less than 8 hours before the next dose is due. In this case, leave out the missed dose and take your next dose at the usual time.
Do not take 2 doses at the same time. Never take an extra dose to make up for a forgotten one.
If you have epilepsy, it's important to take this medicine regularly. Missing doses may trigger a seizure.
If you forget to take your tablets for more than 5 days in a row, speak to your doctor, as you'll need to start on a low dose again and gradually increase to your usual dose.
If you forget doses often, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.
If you take too much
Taking too much lamotrigine can lead to symptoms such as:
- rapid, uncontrollable eye movements
- feeling clumsy or losing your balance
- feeling a change in the rhythm of your heartbeat
- having a seizure (fit)
- passing out
Urgent advice: Contact 111 for advice now if:
- you take more than your prescribed dose of lamotrigine
Go to 111.nhs.uk or call 111. If you need advice for a child under the age of 5 years, call 111.
If you have to go to A&E, do not drive yourself. Get someone else to drive you or call for an ambulance.
Take the lamotrigine packet or the leaflet inside it, plus any remaining medicine, with you.
Stopping lamotrigine
Do not stop taking lamotrigine without talking to your doctor.
If you're taking lamotrigine for epilepsy, stopping it suddenly can cause seizures. Coming off lamotrigine should be done very slowly and might take a few months.
If you're taking lamotrigine for bipolar disorder, it's usually safe to stop taking it without having to reduce your dose first.
If you get a serious side effect, such as a severe skin rash, your doctor may tell you to stop taking lamotrigine straight away, even if you have epilepsy.