Lamictal (lamotrigine)

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How does it work?

Lamictal tablets and dispersible tablets contain the active ingredient lamotrigine, which is a medicine used to treat epilepsy. (NB. Lamotrigine is also available without a brand name, ie as the generic medicine.) Lamotrigine works by stabilising electrical activity in the brain.

The brain and nerves are made up of many nerve cells that communicate with each other through electrical signals. These signals must be carefully regulated for the brain and nerves to function properly. When abnormally rapid and repetitive electrical signals are released in the brain, the brain becomes over-stimulated and normal function is disturbed. This results in fits or seizures.

Lamotrigine prevents epileptic fits by preventing excessive electrical activity in the brain. It does this by preventing sodium from entering nerve cells when they begin to fire rapid and repetitive electrical signals. A build up of sodium in the nerve cells is necessary for the electrical signal to build up and be passed on to other nerve cells. As lamotrigine prevents this, it helps stabilise the electrical activity in the brain.

Preventing the build-up of the electrical signal also prevents the release of a neurotransmitter called glutamate from the nerve cells in the brain. Neurotransmitters are chemicals that are stored in nerve cells and are involved in transmitting messages between the nerve cells. Glutamate is a neurotransmitter that acts as a natural 'nerve-exciting' agent. It is released when electrical signals build up in nerve cells and subsequently excites more nerve cells. It is thought to play a key role in causing epileptic seizures. Reducing the release of glutamate from the nerve cells in the brain is another way in which lamotrigine helps stabilise the electrical activity in the brain and prevent epileptic fits.

In addition to its licensed use for treating epilepsy, lamotrigine is used off-licence by specialists as a mood stabiliser for treating people with the psychiatric illness, bipolar affective disorder. This use is not licensed, but the medicine has been shown to be effective in people with bipolar disorder who have not responded to the traditional mood stabilisers (lithium, carbamazepine, valproate). Lamotrigine is used for treating episodes of high or low mood and for helping to prevent episodes of ill health in these people. It is not fully understood how lamotrigine works in this illness, but is thought to be to do with the reduction of glutamate in the brain.

Lamictal tablets should be swallowed whole with a drink of water. Lamictal dispersible tablets may be chewed, dispersed in a small volume of water (at least enough to cover the whole tablet) or swallowed whole with a little water.

What is it used for?

- Generalised tonic-clonic seizures
- Partial seizures
- Type of severe childhood epilepsy (Lennox-Gastaut syndrome)
- Mood stabiliser in bipolar affective disorder (unlicensed use).

Warning!

- Adverse skin reactions have been reported with lamotrigine. These reactions are usually mild and get better on their own, but can on rare occasions be more serious and potentially life-threatening. The risk is higher in children under 12 years of age and in people who are also taking the medicine valproate. When starting treatment with lamotrigine the dose is increased gradually to minimise the risk of developing a skin rash. For this reason it is very important to follow the instructions you are given with this medicine, and not to exceed the prescribed dose. If you or your child develop a rash, fever, facial swelling or swollen glands while taking this medicine you should consult your doctor immediately. If the doctor decides the reaction is related to this medicine you will need to stop taking it.
- You should not stop taking this medicine suddenly unless your doctor tells you otherwise, as this may result in your seizures returning or getting worse. If it is decided that you should stop taking this medicine, it should be withdrawn gradually, following the instructions given by your doctor. If for any reason you stop treatment for longer than five days and then restart, your doctor may want you to increase your dose gradually, as when you first started the medicine, to minimise the risk of getting a skin reaction.
- This medicine may cause dizziness and double vision. As a result it could reduce your ability to drive or operate machinery safely. You should discuss this with your doctor. Do not drive or operate machinery until you know how this medicine affects you and you are sure it won't affect your performance.
- This medicine may rarely cause a decrease in the normal amounts of blood cells in the blood. For this reason you should consult your doctor immediately if you experience any of the following symptoms: unexplained bruising or bleeding, purple spots, sore throat, mouth ulcers, high temperature (fever), feeling tired or general illness. Your doctor may want to take a blood test to check your blood cells.
- The safety and efficacy of this medicine in children under two years of age has not been established by the manufacturer.

Use with caution in

- Elderly people
- Decreased liver function
- Kidney failure
- Parkinson's disease
- History of allergic reactions or rash due to other antiepileptic medicines.

Not to be used in

- Known sensitivity or allergy to any ingredient.

This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy. If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

- It is vital that women with epilepsy receive specialist advice before getting pregnant, so they are well informed of potential risks and benefits of continuing antiepileptic treatment during pregnancy. Pregnant women taking antiepileptic medicine have a higher risk of carrying a baby with developmental problems and malformations. However, if a woman with epilepsy stops treatment because she is pregnant, there is a risk of seizures that can harm both mother and baby.
- If you decide to try for a baby while taking lamotrigine you should seek medical advice from your doctor as soon as possible. It may be recommended that you start taking folic acid 5mg daily as soon as contraception is stopped, as this may reduce the risk of neural tube defects such as spina bifida in the baby.
- Women who continue to take lamotrigine during a pregnancy should, wherever possible, be prescribed lamotrigine on its own, in the lowest effective dose. Your doctor may need to adjust your lamotrigine dose from time to time, because changes to your body during pregnancy may affect the amount of lamotrigine in your blood and its effectiveness.
- Lamotrigine passes into breast milk. Mothers who need to take lamotrigine should discuss the pros and cons of breastfeeding with their doctor. You should only breastfeed if the potential benefits of breastfeeding are considered to be greater than the risk of side effects from the medicine on the nursing infant. Seek medical advice from your doctor.

Label warnings

- Do not stop taking this medication except on your doctor's advice.

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