anti-epileptic drugs for adults
Most people with epilepsy take anti-epileptic drugs (AEDs) to stop or reduce the number of seizures they have. This page looks at the drugs available for the treatment of epilepsy in adults and children aged 13 and over.
What is the aim of anti-epileptic drugs (AEDs)?
AEDs are used to stop seizures happening. They make the brain less likely to have seizures by reducing the excessive electrical activity - or excitability - of the neurones (nerve cells) that normally cause a seizure. They are not used to stop seizures while they are happening and they do not cure epilepsy.
Different AEDs work in different ways but they all aim to stop seizures happening.
Around 70% (70 in 100) of people with epilepsy could stop having seizures (known as good seizure control) with the right medication. This depends on the type of epilepsy they have.
'Optimal therapy' is seizure control using the smallest dose of the fewest AEDs, with the fewest side effects.
Managing epilepsy can often be a balance between stopping seizures and keeping side effects to a minimum. Getting seizure control can sometimes take a while to happen. It can take time to find the right drug at the right dose, this can vary from one person to another.
Some people may not get complete seizure control, even though they have had the most suitable drug treatment. In this case they may need to take more than one type of AED to reduce seizures as much as possible, while still keeping treatment as simple as possible. This reduces the chances of side effects.
Before starting on AEDs, it is important that your neurologist finds out as much as possible about your epilepsy. This is because the AED that they prescribe depends on the type(s) of seizures you have. Some AEDs work better for certain types of seizures or types of epilepsy than others.
AEDs are taken every day to stop seizures happening. As AEDs may need to be taken over a number of years, the neurologist will take into account any other conditions you have and your lifestyle when prescribing AEDs.
AEDs come with a patient information leaflet. This tells you what the medication is, what it is for and possible side effects.
The National Institute for Health and Clinical Excellence (NICE) recommends that people with newly diagnosed epilepsy are treated with one drug at a time where possible - this is called monotherapy.
AEDs are divided into two categories: first line and second line drugs. First line drugs are usually prescribed when treatment is started. If a first line drug does not stop your seizures happening, a different first line drug may be tried. Alternatively, a second line drug may be prescribed alongside the first line drug, so you take two different types of AED each day. This is called polytherapy. However, if you still have seizures after trying two different AEDs, then your neurologist may review your diagnosis before suggesting other AEDs to try.
Usually AEDs are started at a low dose that will slowly be increased, if needed, until the most effective dose is found. This varies from one person to another. Your seizures and how you feel on the drug will be monitored. This is sometimes called an 'individual therapeutic concentration'.
Our table of anti-epileptic drugs shows the average range of daily doses of different AEDs. The dose you take may be higher or lower than the average dose.
Suddenly stopping AEDs can cause seizures to start again or happen more often and last longer than before. Taking extra AEDs can cause side effects. For these reasons, any changes to AEDs are best done with your neurologist.
Versions of AEDs
Most AEDs have at least two names. They will have a generic name (for example, carbamazepine) and a brand or trade, name given by the manufacturer (for example, Tegretol). Some AEDs have more than one generic version and each version can be given its own name.
For some AEDs, different versions of the generic drug, or different brand versions of the generic drug can vary slightly. This could affect seizure control. For this reason it is recommended to take the same version of AED all the time, whether it is a generic or brand form. This is sometimes called 'consistency of supply'.
If a prescription only has the generic name of the drug, a pharmacist can give any form of the drug with that generic name. However, if the prescription has the brand name of the drug, the pharmacist has to give that brand. To ensure consistency of supply it might be helpful to get the prescription from the same pharmacist each time.
Many pharmacists keep patient medication records and can help with questions about prescriptions. Some can also review medications (called a ‘medicines use review’). If you are not sure if your AEDs are the same as those you normally take, check with the pharmacist or doctor.
Sometimes medication is labelled in a different language or has different packaging than usual. Often this happens if the drug has been made in another country and brought into the UK (a 'parallel import'). Some people find that parallel imports affect their seizure control. If you do not want to take medication that has been imported from outside the UK you have the right to refuse it and ask for a supply from within the UK, if possible for that drug.
It is important to remember that by always taking the same version of a drug there may be less risk of having a seizure. See Getting the right medication which includes a letter to give to your healthcare professional to explain why this is important.
More about generic and branded AEDs
Deciding to start taking medication or not is a personal choice. To help you make a decision, you can discuss with the neurologist the possible risks and benefits of taking, or not taking, the medication. You can also ask to see your neurologist to discuss changing your treatment at a later date.
AEDs work best when they are taken regularly. This is because once taken, they start to be broken down and absorbed into the bloodstream, and go to the brain to start working. As time passes, the drug leaves the body, so the level of drug in the body goes down. Taking the drugs regularly means that the drug is 'topped up' so there is a steadier level in the body all the time. Although the exact timing of doses is not usually crucial, it is helpful to take the right dose around the same time or times each day, so that the doses are evenly spaced out.
For most people, missing one dose on a rare occasion is unlikely to trigger a seizure. If you do miss a dose, see the patient information leaflet for what to do or ask your doctor or pharmacist. If you are sick or have diarrhoea, this may affect how your AEDs are absorbed. Your doctor can advise you. Do not take a double dose to make up for a missing dose.
Some drugs are slow-release, these are called chrono or prolonged release (also sometimes called CR or controlled release). Examples of these are Epilim Chrono or Tegretol Prolonged Release. In slow-release drugs, the active ingredient is released more gradually and is taken less often than non-chrono versions.
Some AEDs come in a number of forms: tablets, capsules, syrups or suppositories. There are also forms that can be added to food (such as sprinkles or granules) which can be useful if you have difficulty swallowing tablets. You can talk to your neurologist or pharmacist about what forms are available for your AED. (For more information see our table of anti-epileptic drugs.)
See more about taking AEDs including tips which might help you to take your AEDs and to get the best out of them.
Drug wallets (pill organisers) can help you to take the right dose at the right time. They usually have seven containers to keep medication in (one for each day of the week). Each container is divided into sections for the morning, afternoon and evening. Dispersible tablets (that dissolve in water) can't be stored in drug wallets because they react to the air.
You can buy drug wallets via our online shop.
All medications can cause side effects. Whether or not someone develops side effects depends on their individual reaction to the medication. Side effects can vary from person to person and from drug to drug. It is important to balance any side effects against the seizure control the medication gives.
Some people have allergic reactions to medication. This is rare but can be serious. A skin rash is often the first sign of an allergic reaction and usually happens soon after starting treatment. If you think you have an allergic reaction, contact your doctor as soon as possible.
Dose-related side effects happen if the dose is too high. Starting medication at low doses and increasing it slowly may avoid this. Some side effects happen when starting new AEDs. These normally wear off after a few days or weeks. If you have side effects that continue, it is worth talking to your doctor about this.
If drugs are taken for a long time (many years), long-term side effects may happen. Keeping drug treatment as simple as possible may lower the risk of these effects.
The Yellow Card Scheme
The Medicines and Healthcare products Regulatory Agency (MHRA) ensures the safety of medications licensed for use in the UK. The Yellow Card Scheme is a way of reporting side effects to the MHRA, particularly any not listed in the patient information leaflet. You can get a Yellow Card form from your GP, pharmacy, hospital or NHS drop-in centre, by calling 0808 100 3352 or online from the Yellow Card Scheme website (opens new window).
AEDs and other medication
Some AEDs affect how other medications work. Some other medications can affect how AEDs work. Telling your doctor about any other medication you are taking helps to avoid any possible interactions (when different drugs affect each other). It can be helpful to check with a pharmacist before taking over-the-counter medications, including complementary therapies such as herbal remedies.
AEDs and alcohol
Whether to drink alcohol when taking AEDs is a personal choice. However, alcohol can trigger seizures, especially during a hangover.
Alcohol can also affect how AEDs work, depending on the AED, the individual and how much they drink. The patient information leaflet often has guidance on drinking alcohol with your medication, or you can ask your doctor about this.
Monitoring AEDs involves checking whether your seizures are controlled or how often they happen and if you have any side effects.
If you have osteoporosis or a family history of osteoporosis, you may be offered a bone density test. This is because some AEDs may affect bone density for some people.
Before starting AEDs you may be asked to have a blood test. This looks at a number of things, including how well your liver is working. This test may be repeated every one or two years.
Therapeutic drug concentration monitoring (TDM) is a way of managing epilepsy treatment. It is done by measuring the amount (concentration) of the drug in the blood. This is done to try and get the best seizure control with the least side effects for each person. Not everyone has TDM as a standard part of their epilepsy management, but TDM can be useful if you:
- are starting a new AED when you are already on one
- take more than one AED
- are still having seizures
- have been seizure-free but your seizures start again
- have other medical conditions, take other medications, or have poor liver or kidney function
- have a learning disability or find it hard to explain how your AEDs make you feel
- are pregnant
- are over 60 years of age
- are taking phenytoin (an AED that is unusual in how it is distributed around the body and TDM can help to check this).
Find out more about monitoring epilepsy and TDM.
Coming off AEDs
Some people may need to take AEDs for a long time, sometimes many years. If someone has not had a seizure for two or more years then they may be able to think about withdrawing (coming off) their AEDs.
If you are thinking of coming off your AEDs, this is best done with advice from your neurologist. Stopping treatment can lead to seizures starting again and sometimes they may last longer than they did before. Your neurologist can help you to plan your withdrawal and advise you on what to do if your seizures start again. For most people, if seizures do start again, taking the same AED straight away usually gives the same seizure control as before. But sometimes the AED may not work as well as before.
Considering the impact on your life if your seizures start again, such as the effect on work, leisure and driving, may be an important part of deciding whether to come off your AEDs.
Most people do not have withdrawal symptoms if a drug is withdrawn slowly. However, AEDs that might cause withdrawal symptoms include phenobarbital, diazepam, clonazepam, clobazam and phenytoin. Symptoms can include anxiety, panic, restlessness and sweating.
Contraception, pregnancy and AEDs
Some types of contraception are less effective for women taking some AEDs. This depends on the individual, which AEDs they take and the type of contraception they use. There is also a chance that taking AEDs while pregnant may affect the developing baby. However, these risks need to be carefully considered for each person and balanced against the possibility of seizures happening during pregnancy, which may also affect a developing baby or the safety of the mother.
Usually a seizure will stop by itself. However, if a seizure continues for more than 30 minutes (or one seizure follows another with no recovery in between) this is known as status epilepticus (or 'status').
Seizures that last longer than usual, or an increased number of seizures, often happens before an episode of status. For some people, missing doses of AEDs can trigger status. Status in a tonic clonic (convulsive) seizure is a medical emergency and needs urgent treatment with emergency medication.
The two emergency medications used to prevent status in the community (outside of the hospital setting) are midazolam and diazepam.
For people who have gone into status before, their doctor may prescribe midazolam or diazepam so that a carer can give it to them. Specialist training is needed to give emergency medication.
Find out more about emergency medication including our booklets and training for carers.
Epilepsy is a very individual condition and people respond differently to their treatment. NICE recommends that if you have epilepsy you should have a review at least once a year, with either your GP or neurologist. The review should look at whether you are seizure-free or how well your seizures are controlled by the AEDs you take, any side effects you have and any concerns you may have.
A note on prescriptions
In England, people with epilepsy are entitled to free prescriptions for their AEDs and any other medication (called ‘medical exemption’). To apply, fill in an FP92A form from your GP surgery. Everyone in Scotland, Wales and Northern Ireland gets free prescriptions.
Taken from our Medication for adults leaflet. Order this leaflet from our online shop as part of our 'first five free' offer.
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