Lamotrigine

What is lamotrigine used for?

Lamotrigine (brand name Lamictal) is a prescription-only medicine used to treat epilepsy and low-mood in people with bipolar disorder. It belongs to a group of medicines called antiepileptic drugs (AEDs) and can act as a mood stabiliser[1]. 

It is commonly prescribed to[1]: 

• Prevent and control seizures in epilepsy (including focal, generalised, and Lennox-Gastaut syndrome) 

• Prevent episodes of depression in people with bipolar disorder (but not typically used to treat manic episodes in bipolar disorder) 

How does lamotrigine work?

Seizures are bursts of electrical activity in the brain that temporarily interrupts how it normally works. Lamotrigine helps stabilise the electrical activity in the brain by[1]: 

• Slowing the signals down 

• Blocking sodium channels which are involved in sending these signals 

• Reducing the release of glutamate (a chemical messenger that can trigger seizures and mood swings) 

Who can take lamotrigine?

Lamotrigine can be used by both adults and children 2 and older (age limits vary depending on the condition being treated)[1]. 

You should not take lamotrigine if you[1]: 

• Are allergic to lamotrigine or any of its ingredients 

• Have liver or kidney problems 

• Have bipolar and/or have ever had suicidal thoughts 

• Have ever had meningitis or a rash caused by lamotrigine 

• Are pregnant, trying to get pregnant, or are breastfeeding 

Please tell your doctor or pharmacist about any conditions you may have or medication you take before you start treatment, and always follow the instructions in the Patient Information Leaflet[2]. 

What is the typical dosage of lamotrigine?

The usual dose of lamotrigine for epilepsy is[1]: 

• For adults and older children (aged 12 years and over) – 100mg to 700mg a day, taken as 1 or 2 doses 

• For younger children (aged 2 to 11 years) – the dose will vary depending on their weight 

The usual dose for adults with bipolar disorder i[1]s: 

• between 200mg and 400mg a day, taken as either 1 or 2 doses 

When you take lamotrigine, it’s important that the dose is increased slowly to help reduce or stop side effects. Once you and your doctor or pharmacist settle on a dose that suits you best, it will usually stay the same for the duration of your treatment[1]. 

How do you take lamotrigine?

Lamotrigine can be taken once or twice a day. You can take it with or without food. Try to take it at the same time each day to help maintain steady levels in your body.  

It comes in[1]: 

• Standard tablets (swallowed whole) 

• Dispersible/chewable tablets (can be chewed or dissolved in water) 

Can you stop taking lamotrigine?

Do not stop taking lamotrigine suddenly unless told to by your doctor. Stopping it abruptly can lead to serious problems, such as seizures or mood changes. Your doctor will help you reduce your dose gradually if needed[1]. 

• For sleep problems, 20mg to 50mg at bedtime is the usual dose

• For vertigo, the dose can vary from 25mg a day to 25mg 4 times a day as prescribed

Children and some adults may have a lower dose. You should always follow the dose recommended by your doctor, pharmacist or as listed on the packaging.

What to do if you take too much lamotrigine

Taking too much lamotrigine can be dangerous. Symptoms of overdose may include[1]: 

• Clumsiness or loss of balance 

• Heartbeat changes 

• Blurred vision, or rapid, uncontrolled eye movements 

• Seizures 

• Loss of consciousness 

Call 999 or go to A&E immediately if you suspect an overdose. 

What to do if you forget a dose of lamotrigine?

If you forget a dose[1]: 

• Take it as soon as you remember 

• If it’s nearly time for your next dose, skip the missed one 

• Do not take two doses at once 

If you miss several doses, contact your doctor for advice – you may need to restart at a lower dose[1]. 

Medicines you can’t take with lamotrigine

Lamotrigine can interact with several medicines, including[1]: 

• Other epilepsy medication, such as valproate (increases lamotrigine levels), or carbamazepine and phenytoin (decrease lamotrigine levels) 

• Hormonal contraceptives (can reduce the effectiveness of both the pill and lamotrigine) 

• HIV medication 

• Rifampicin (for tuberculosis) 

• Bupropion (smoking cessation aid) 

• Mental health medication (such as aripiprazole, lithium, olanzapine or risperidone) 

• The combined contraception pill 

Avoid taking herbal remedies like St John’s Wort unless approved by your doctor. Always inform your doctor or pharmacist about all medications and supplements you take before you start a new medicine, and follow the instructions in the Patient Information Leaflet[2].  

What are the side effects of lamotrigine?

The most common side effects include[1]: 

• Headache 

• Dizziness 

• Nausea or diarrhoea 

• Sleepiness or difficulty sleeping 

• Aggression or irritation 

• Tremors 

• Rash (can be serious – contact your doctor immediately if you develop a rash) 

Serious but rare side effects include[1]: 

• Stevens-Johnson syndrome (a life-threatening skin reaction) 

• Suicidal thoughts or behaviours 

• Blood disorders 

• Liver problems 

You should contact your GP if you experience any of these symptoms. In rare cases, the medicine may cause a serious allergic reaction (anaphylaxis). You should call 999 or visit A&E immediately if you believe this is happening[1]. 

Symptoms of anaphylaxis include:  

• Difficulty breathing  

• Tightness in throat and chest  

• Swelling of the tongue or throat  

• Feeling faint or dizzy  

• Blue/grey skin or lips  

• Loss of consciousness 

If you experience any side effects, including those not listed, you are encouraged to report them via the Yellow Card Scheme or contact your doctor, pharmacist, or nurse. This information is intended as a summary for general awareness and does not replace professional medical advice. 

The information provided in the side effects section is not a comprehensive list of all possible side effects associated with this medication. For a complete list of side effects, please refer to the Patient Information Leaflet (PIL) provided with your medication or consult your healthcare professional[2]. 

Frequently asked questions about lamotrigine

Can I drink alcohol while taking lamotrigine? 

Yes, but alcohol can increase side effects such as dizziness and drowsiness. Drink in moderation and see how you feel[1]. 

Is lamotrigine safe during pregnancy? 

Lamotrigine can be used during pregnancy, but the risks and benefits should be discussed with your doctor[1]. 

Can I drive while taking lamotrigine? 

Yes – but avoid driving if you feel sleepy, dizzy, or have seizures. If you have epilepsy, you must inform the DVLA[1]. 

How long does it take to work? 

It may take several weeks to feel the full effect, especially for mood symptoms in bipolar disorder[1]. 

Will lamotrigine affect my contraception? 

It’s a good idea to speak to your doctor, as lamotrigine can affect the combined pill’s effectiveness. Also, the combined pill, vaginal ring and patch can all lower the amount of lamotrigine in your blood[1]. 

Does lamotrigine work better than other epilepsy medicines? 

There are numerous medicines to treat epilepsy. They have different side effects and work differently, and doses can vary. Your doctor will help you find the best treatment for you[1]. 

For the official NHS guide to lamotrigine, visit their website.