This information is relevant to people who live in the UK.
Epilepsy medicines are often available in different versions made by different companies. For some people, there’s a chance that switching between versions could affect their seizure control or side-effects.
Why are there different versions of my epilepsy medicine?
Many medicines, including most epilepsy medicines, are available in both branded and generic versions.
In the first years that a new medicine becomes available, the company that developed it usually takes out a patent. This means that only they can sell it. This company gives it a brand name. So for the first few years that a new epilepsy medicine is available, the only version is the branded version.
Once the original company’s patent runs out, other companies can start making their own versions of the medicine. These medicines are known as generic or non-proprietary medicines. There can be many different generic versions of the same epilepsy medicine. Most will use the name of the active ingredient, but occasionally a company will give their generic version its own brand name. These are known as branded generics.
Doctors are encouraged to prescribe generic medicines where appropriate, as generic medicines tend to be cheaper for the NHS. This is called generic prescribing. It means your pharmacist can give you any company’s version of your medicine.
Using the epilepsy medicine levetiracetam as an example, the branded version is called Keppra. But there are also a number of generic versions with the name levetiracetam.
See a full list of epilepsy medicines, including their generic and brand names.
Are there any differences between different versions of my epilepsy medicine?
Whatever version of epilepsy medicine you have, the active ingredient should be the same. For example, every version of levetiracetam 250mg tablets should contain 250mg of levetiracetam. However, all medicines have other ingredients as well as the main one. These other ingredients can be different, depending on who makes the medicine. Different versions of a medicine will also look different and have different packaging.
Could switching between different versions of my medicine be a problem?
It’s possible that for some types of epilepsy medicine, small differences between versions could affect how the medicine is absorbed and how well it works. Many people with epilepsy have no problems when switching between different versions of their medicine. But for some people, switching between different versions of their medicine could cause them to have an increase in seizures, or have a breakthrough seizure after being seizure free. Some people might have different or more side-effects. The risk varies depending on which medicine you take.
What is the guidance about switching between versions of my medicine?
The Medicines and Healthcare products Regulatory Agency (MHRA) has published guidance about prescribing epilepsy medicines. The guidance puts epilepsy medicines into 3 categories, based on the risk that switching between versions could lead to seizures or side-effects. This is what the MHRA says about prescribing medicines in each category:
If you take one of these medicines, your doctor should make sure you stay on the same version.
For these medicines, your doctor should use their clinical judgement and consult you and/or your carer when deciding whether you need to stay on the same version. The doctor should consider things like how frequent your seizures are and your treatment history. If you are seizure free, they should consider what impact having a breakthrough seizure would have. They should also take into account the other factors explained in category 3.
If you take one of these medicines, the MHRA says there’s usually no need to stay on a particular drug company’s version. This is because differences between versions should not cause any problems with seizures or side-effects. But your doctor should consider other factors when deciding if you should stay on the same version. They should consider if differences in product name, packaging, appearance, and taste could lead to dissatisfaction, anxiety, confusion, dosing errors, or not taking medicine. They should also consider difficulties for patients with autism, mental health problems, or learning disabilities.
How can I get the same version of my epilepsy medicine?
If you and your doctor agree you should stay on the same version of your medicine, your doctor can write the brand name on your prescriptions. Or, if you want to stay on a particular manufacturer’s generic version, the doctor can write the generic name and the name of the manufacturer on your prescription. Your pharmacist should always try to give you the version your doctor has written on your prescription.
What if I can’t get the version of epilepsy medicine I usually take?
Sometimes your pharmacist might not be able to get your usual version of epilepsy medicine. There can be a number of reasons for this, including:
- The manufacturer has run out of stock, perhaps because of a manufacturing problem or an increase in demand
- The wholesalers that supply your pharmacy are out of stock
- The manufacturer or wholesaler allows a certain amount of stock for each pharmacy (called a quota), and your pharmacy has reached the limit of how much it can order
- The manufacturer has stopped making the medicine
If your pharmacist doesn’t have your usual version in stock, you can ask for your prescription back and take it to another pharmacy. But if your usual version isn’t available anywhere, you may have no choice but to take a different version. If you have any worries about taking a different version, your doctor should be able to give you advice. For most people, it is safer to take a different version of their medicine than to run out and stop taking medicine suddenly.
For the latest updates on epilepsy medicine shortages, visit our drugwatch page.
We are often asked if the UK’s exit from the EU (Brexit) will lead to shortages of epilepsy medicine. We are monitoring the progress of negotiations between the UK and EU and engaging with government on the issue of medicine supply. For the latest news visit our epilepsy and Brexit blog.
How can I report problems with my epilepsy medicines?
If you think you are getting side-effects from your epilepsy medicine, or they have caused your epilepsy to change, talk to your GP. They can report these issues to the MHRA. You can also report side-effects yourself by completing a Yellow Card. These are available from your GP, pharmacist or the Yellow Card scheme:
Tel: 0800 731 6789 (10.00am – 2.00pm Monday – Friday)
If you would like to see where our information is from, download a copy of this information with references.
Epilepsy Action would like to thank thank Dr John Paul Leach, consultant neurologist at the Queen Elizabeth University Hospital, Glasgow, for his contribution to this information.
Dr John Paul Leach has declared no conflict of interest.
This information has been produced under the terms of Epilepsy Action's information quality standards.
- Updated December 2020To be reviewed December 2023