Anti-epileptic drug treatment

• Introduction to anti-epileptic drugs
• List of AEDs available in the UK
• Starting treatment with anti-epileptic drugs
• Taking your anti-epileptic drugs
• Doses of anti-epileptic drugs
• How long it takes for anti-epileptic drugs to work
• Side-effects of anti-epileptic drugs
• Anti-epileptic drugs and your bones
• Anti-epileptic drugs and contraception
• The Yellow Card Scheme
• Changes in how well anti-epileptic drugs work
• Changing anti-epileptic drugs
• Interactions between anti-epileptic drugs
• Drug level monitoring
• Stopping anti-epileptic drug treatment

Introduction to anti-epileptic drugs

The most common way epilepsy is treated is with anti-epileptic drugs (AEDs). AEDs do not cure epilepsy, but aim to try and stop seizures happening. AEDs are taken at regular times each day.

Starting treatment with anti-epileptic drugs

There are many different anti-epileptic drugs (AEDs) available. Your epilepsy specialist will recommend the most appropriate one for you. To choose the AED, the specialist will look at things like the type of seizures you have, and if you have any other medical conditions.

• See a list of AEDs available  in the UK

Doctors usually try to avoid prescribing more than one AED at a time. This is because the more drugs you take, the higher the risk of having side-effects. There may be times, however, when you need to take two or more AEDs. For example, when you change from one AED to another. Or, if the doctor thinks that having an additional AED would help to control your seizures better.

Taking your anti-epileptic drugs

Most anti-epileptic drugs (AEDs) come as tablets, capsules, liquids and chewable or crushable tablets. If you find tablets difficult, you can ask your doctor to prescribe you something that you would find easier to swallow.

AEDs are usually taken once or twice a day. Sometimes they are taken three times a day. It’s important to take your AEDs regularly, as prescribed by your doctor. This is to keep as steady a level of the drug in your blood as possible. If you miss taking your AEDs this can sometimes trigger a seizure.

It’s a good idea to get advice about what you should do if you ever forget to take your AEDs. You could speak to your epilepsy specialist, family doctor or epilepsy nurse about this. The advice they give you will depend on which AED you are taking and the dose. They will also consider any other medical conditions you have, or medicines you are taking, that might affect your epilepsy.

Doses of anti-epileptic drugs

Your doctor will tell you how much of your anti-epileptic drug (AED) you should take. It’s usual to start an AED at a low dose and gradually increase it to the maintenance dose. The maintenance dose is the amount of drug which is thought to work well at controlling your seizures.

Each AED has a different usual maintenance dose. For example, the recommended maintenance dose for carbamazepine is between 800 and 1,200 milligrams (mg). For zonisamide it is between 300 and 500 mg.

It may take a few weeks or months to get to the maintenance dose of your AED. By starting the drug at a lower dose and gradually increasing it, this allows your body to slowly get used to the drug. This lowers the risk of getting side-effects.

Sometimes, your doctor may suggest that you take a higher or lower dose than the usual maintenance dose. This might be to get better control of your seizures or reduce the risk of side-effects.

How long it takes for anti-epileptic drugs to work

Many people with newly-diagnosed epilepsy respond well to anti-epileptic drugs (AEDs). This means that they have fewer seizures, or the seizures stop altogether. It’s not possible to say how long this will take. Many people find the right AED and dose very quickly. For some people it can take a lot longer.

About 30 in every 100 people with epilepsy have seizures that do not respond well to AEDs. They continue to have a number of seizures, even though they have tried two or more AEDs.

Side-effects of anti-epileptic drugs

Like most drugs, anti-epileptic drugs (AEDs) can cause side-effects. The risk that you will have side-effects depends on a number of things, including which AED you take and any other medicines you take.

In the UK, when you start taking an AED, your doctor or pharmacist should give you a patient-information leaflet (PIL), by law. The PIL lists all the possible side-effects of that drug. Although you could get any of those side-effects, most people get few or mild side-effects. Some people do not get any side-effects at all.

There is more risk that you will get side-effects in the early days of taking an AED. Once your body has had a few days or weeks to get used to the AED, these side-effects should lessen or disappear completely. If they don’t, talk to your family doctor or epilepsy specialist. They may be able to make changes to your AEDs to lessen the side-effects.

You can find information about side-effects of individual AEDs on the Medicine Guides website.

Anti-epileptic drugs and your bones

The anti-epileptic drugs carbamazepine, phenobarbital, phenytoin, primidone, sodium valproate and topiramate may cause your bones to become thinner and more brittle. This means you are more at risk of breaking them.

If you are concerned that you may be at risk of having weaker bones, it’s a good idea to talk to your family doctor. They can suggest ways you can look after your bones, such as taking vitamin supplements and exercising, if this is suitable for you.

• More information about epilepsy and your bones

Anti-epileptic drugs and contraception

If you are a woman with epilepsy, it is advisable to plan any pregnancy very carefully. This is to make sure that the pregnancy is as healthy as possible for both you and your baby. Some anti-epileptic drugs (AEDs) make the contraceptive pill work less well. This could lead to an unplanned pregnancy. These AEDs include carbamazepine, eslicarbazepine acetate, lamotrigine, oxcarbazepine, phenobarbital, phenytoin, primidone, rufinamide and topiramate.

The contraceptive pill can also interact with the AED lamotrigine and cause the amount of lamotrigine in your blood to drop. This can increase the risk of seizures.

• More information about contraception and epilepsy
• More information about planning a baby and epilepsy

The Yellow Card Scheme

If you live in the UK and think that you are getting side-effects from your anti-epileptic drugs (AEDs), it’s advisable to talk to your GP (family doctor). Your GP may report the side-effects to the Medicines and Healthcare products Regulatory Agency (MHRA).

Alternatively, you can report side-effects yourself by completing a Yellow Card. These are available from your GP or pharmacist or through NHS Direct or the Yellow Card website and hotline.

Changes in how well anti-epileptic drugs work

A small number of people with epilepsy may find that their anti-epileptic drug (AED) stops working as well as it once did. There can be a number of reasons for this.

• The person may not be taking their AED regularly.
• The person’s epilepsy itself may have changed.
• The cause of the person’s epilepsy may have changed.
• The person’s body may have got used to the AED, so it no longer works.

If you live in the UK and your AEDs are not stopping or reducing your seizures, the National Institute for Health and Clinical Excellence (NICE) makes some recommendations. They recommend that your GP (family doctor) should arrange for you to have an appointment with an epilepsy specialist. The specialist may be able to suggest changes to your treatment to try and get better control of your seizures.

If you have to wait a long time to see your epilepsy specialist, it’s important that you do not make any changes to your AEDs yourself. This could cause you to have more seizures. You could ask your family doctor or epilepsy specialist nurse for advice about taking your AEDs while you are waiting to see your epilepsy specialist.

Changing anti-epileptic drugs

You may have been taking an anti-epileptic drug (AED) for a while and still be having seizures, or experiencing side-effects. If this is the case, talk to your family doctor or epilepsy specialist. They may suggest that you try a new AED.

The recommended way to change to a different AED is to start taking a new AED as well as your old AED. Once you are taking the right dose of the new AED, the old AED is gradually reduced. This way of changing AEDs is to make sure that there is always enough medicine in your body to control seizures.

It’s important to bear in mind that when changing AEDs there is a risk that you could have more seizures than usual. This could be because the new drug does not work well for you. Because of this, your doctor may advise you to stop driving for a period of time. If you live in England, Scotland or Wales you may need to stop driving for up to six months. If you live in Northern Ireland, you will have to stop driving for at least six months. You may also decide to avoid activities such as some sports, until you and your doctor feel sure that the new AED is working well.

• More information about epilepsy and driving

Interactions between anti-epileptic drugs

If you take more than one anti-epileptic drug (AED), it’s possible for one AED to raise or lower the amount of a different AED in your blood. For example, carbamazepine (Tegretol) may reduce the amount of sodium valproate (Epilim) in your blood. This could cause you to have more seizures.

If you take more than one AED, and your doctor suggests that you change the dose of one of them, they may also advise you to change the dose of the other.

Drug level monitoring

Drug level monitoring involves having regular blood tests to check how much of a drug is in a person’s blood.

It’s not usual for doctors to do drug level monitoring for anti-epileptic drugs (AEDs). This is because the tests do not usually provide helpful information about most AEDs. The exception to this is phenytoin. Blood tests can help doctors make sure that a person is taking the right dose of this particular AED.

Occasionally, doctors may do blood tests to see if a person is taking their AEDs regularly. They may also do a blood test if they think a person is getting side-effects because the dose of their AED is too high. Blood tests may also be done for people who take AEDS who are going to have surgery, or for pregnant women.

Stopping anti-epileptic drug treatment

Some people have to take anti-epileptic drugs (AEDs) for the rest of their life, even if they no longer have seizures. Other people can stop taking AEDs when they have been seizure-free for a few years. It’s important not to stop taking your AEDs without getting advice from your epilepsy specialist.

If you want to try and stop taking your AEDs, you and your epilepsy specialist will need to consider a number of things. These include whether there is a physical cause for your epilepsy and how long it took for your seizures to stop. This information can help your specialist decide what the risks of your seizures coming back would be if you didn’t take AEDs.

If your epilepsy specialist recommends that stopping AEDs is right for you, they will usually advise you to stop taking them very gradually. This may take a few months. If you suddenly stop taking them, this could cause you to have more frequent and severe seizures.