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Getting the same version of your epilepsy medicine every time

This information is relevant to people who live in the UK.

Epilepsy Action believes that you should get the same version of your epilepsy medicine, whenever possible, every time you pick up a prescription. Having the same version is known as consistency of supply.

Generic and brand names

Nearly all medicines have a generic name and a brand name. The generic name is the name of the main ingredient. The brand name is given by the company that makes the medicine.

In the first years that a medicine becomes available for patients, it is under licence. This means that only the company that researched and developed it can sell it. This company gives it a brand name.

Once the licence runs out, any drug company can make the medicine. These medicines are called by the generic name and are known as non-proprietary medicines. They may be cheaper than branded ones. Some companies who make the medicine once the original licence runs out, give it their own brand name. These are known as branded generics.

For example, with carbamazepine:

First version: The first and original version of carbamazepine has the brand name Tegretol®.

Later version: A later version made by another company has the brand name Carbagen®. This is a branded generic.

Generic versions: There are also several generic or non-proprietary versions. These all have the generic name carbamazepine and no brand name.

Whatever version of epilepsy medicine you have, the active ingredient should be identical. So, every version of carbamazepine 100mg tablets should contain 100mg of carbamazepine. However, all medicines have other ingredients as well as the main one. These other ingredients can be different, depending on who makes the medicine. For some people, this difference could affect how well the medicine works. It could also mean they experience more or different side-effects.

Prescribing by brand

If a doctor writes a brand name on your prescription, the pharmacist must give you that specific brand.

Generic prescribing

If a doctor writes the generic name of your medicine on your prescription, a pharmacist can give you that medicine from any drug company. This is called generic prescribing. There is increasing pressure on the NHS to reduce its costs in many areas. One area is prescribing costs. Because generic medicines can be cheaper than branded versions, doctors and other prescribers may want to switch some people onto those cheaper versions.

Possible issues with generic prescribing

Some people say they have no problem with taking different versions of their epilepsy medicine. However, some people who have switched to a different version of their epilepsy medicine have told us that they have had seizures after being seizure-free for some time. And some people have had more seizures and/or side-effects that they haven’t had before.

Advice for people who prescribe epilepsy medicine

The Medicines and Healthcare products Regulatory Agency (MHRA) is an agency of the Department of Health. In 2017 they updated their guidance on prescribing epilepsy medicines. This followed a review by the Commission on Human Medicines (CHM) which looked at the evidence on patients switching between different manufacturers’ products of particular epilepsy medicines.

CHM advise that epilepsy medicines can be classified into three categories. This classification aims to help prescribers and patients decide whether it is necessary to maintain consistency of supply of a specific company’s product. It is not official policy, but guidance only.  

The MHRA’s guidelines about prescribing epilepsy medicines

Epilepsy medicine


Category 1

  • Carbamazepine
  • Phenobarbital
  • Phenytoin
  • Primidone


It has been shown that the differences between different drug companies’ products could affect seizure control and/or side-effects. Prescribers should ensure a specific drug company’s product is always prescribed.

Category 2

  • Clobazam
  • Clonazepam
  • Eslicarbazepine
  • Lamotrigine
  • Oxcarbazepine
  • Perampanel
  • Retigabine
  • Rufinamide
  • Topiramate
  • Valproate
  • Zonisamide

Whether to always have a specific drug company’s product should be based on what is right for the individual. Prescribers should talk this through with their patient and/or carer. They should look at things like seizure frequency and treatment history. They should also take into account how their patient and/or carer feels about being prescribed different versions of their epilepsy medicine.

Category 3

  • Brivaracetam
  • Ethosuximide
  • Gabapentin
  • Lacosamide
  • Levetiracetam
  • Pregabalin
  • Tiagabine
  • Vigabatrin

The likelihood of there being any differences that could affect seizure control and/or side-effects between different manufacturers' products is considered to be extremely low. However, prescribers should look at each patient individually, taking into account how they and/or their carers feel about being prescribed different versions of their epilepsy medicine. 

How to get the same version of your epilepsy medicine

The most reliable way to get the same version is to ask your doctor to 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.

If you take an epilepsy medicine that is in category1, your prescriber should ensure you always have the same version of your medicine. If you take an epilepsy medicine in categories 2 or 3, your prescriber might want to give you a generic prescription. However, the current guidelines say that they should also take into account how you feel about having a different version.

What if I can’t get the version of epilepsy medicine I usually have?

Sometimes there can be a shortage of supplies or a company may stop making a medicine. Unfortunately, where this is the case, there may be no choice but to take a different version. The health professional who usually prescribes your epilepsy medicine should be able to advise you what to do in this instance.

What about serious shortage protocols?

If there is a serious shortage of a particular medicine, the government can issue a serious shortage protocol (SSP). An SSP gives pharmacists extra powers to manage the medicine shortage.

In some cases an SSP could allow pharmacists to switch people from one medicine to another, without consulting their doctor. However, the government says pharmacists will not be allowed to do this with epilepsy medicines. In the event of the government issuing an SSP for your epilepsy medicine, pharmacists may do one of the following things to manage the shortage:

  • Give you a different strength of your medicine to make up your usual dose – for example, if you usually take a 10mg tablet, you might be given 5mg tablets and told to take 2 tablets instead of one
  • Give you a reduced amount of your medicine – for example if you are normally prescribed a 6 week supply you might be given a 4 week supply instead
  • Refer you to your prescribing doctor to see if they will change your prescription

Read more about serious shortage protocols.

Reporting problems with 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)

Website: yellowcard.mhra.gov.uk

If you would like to see this information with references, visit the Advice and Information references section of our website. If you are unable to access the internet, please contact our Epilepsy Action Helpline freephone on 0808 800 5050. 

Page updated with information about serious shortage protocols: April 2019


Epilepsy Action would like to thank Dr John Paul Leach, consultant neruologist, Southern General Hospital, Glasgow for his contribution.

Dr John Paul Leach has declared no conflict of interest.

This information has been produced under the terms of The Information Standard.

  • Updated November 2017
    To be reviewed November 2020

Comments: read the 8 comments or add yours


My boyfriend has just had his 2nd seizure ever today, so they prescribed him Lamotrigine Accord, starting 25mg going up in 2 weeks time. Im struggling to sleep with the panic it will still happen in the morning... does this medicine truly work for people? have people gone seizure free on it? I just want some peace of mind... thanks

Submitted by Kelly Butcher on


I’m sorry to hear that you’re not sleeping well. It’s understandable that this is a worrying time for you.

Many people with newly-diagnosed epilepsy respond well to epilepsy medicine and have fewer seizures. It’s not possible to say how long this will take, but it often happens quickly. And most people with epilepsy can become completely seizure free when taking epilepsy medicine. https://www.epilepsy.org.uk/info/treatment/anti-epileptic-drug-treatment

There are lots of different epilepsy medicines available and everybody reacts differently to different medicines. Around half of people with epilepsy will have their seizures stopped by the first epilepsy medicine they try. But for others it can take a little more trial and error before they find the right medicine or combination of medicines for them.

We have lots of information on our website that you might find helpful, such as information about diagnosis, treatment, seizure types, first aid and daily living.

Some people also find it helpful to talk to, or contact, others who understand what they are going through. You might like to contact one of our local coffee & chat groups if there’s one in your area. We also have our forum4e online community, and are on Facebook and twitter.






And if you think it might be helpful to talk to us you could call our Epilepsy Action Helpline freephone 0808 800 5050. We are open 8.30am-8pm Monday to Thursday, 8.30am-4.30pm Friday and 10am-4pm Saturday.



Epilepsy Action Helpline Team

Submitted by rich on

Just want to register I used to be fine with the branded oxcarbazepine. Then I moved to another country, got the generic version, and it didn’t work. When I went to my country of origin on holidays, I had blood tests done with both drugs (branded and generic), and they did NOT contain the same level of oxcarbazepine. Unfortunately, as I am living abroad, I had to talk to my new neuro to always get the Trileptal. Even then, I never worked again. About that, I have a question: is it possible to have different components in branded drugs manufactured by the same company, in different continents?
To those who are curious, my whole medication scheme got changed, and my neuro lowered the Trileptal, since I started getting dangerously low sodium levels, and put me on clobazam also. The clobazam, by the way, seems to work similarly for me, branded or not.

Submitted by Rachel on

I am on a 'cocktail' including Lamotrigine - and was on Teva, which I had to argue for and my pharmacist made me feel guilty about it. When that ran out, I was given Milpharm, which has been OK, but now I've been given Torrent, and frankly I am uncomfortable with the changes. ( I had a bad experience several years ago with Keppra - which took me completely by surprise, because Keppra is suppose to be completely stable) I don't want to make this one. Any suggestions? I'm getting nervous about opening my bag of medication.

Submitted by Ella AD on


I can understand why you’re concerned about this change in your medicine.

We have checked with Milpharm and they have told us that their lamotrigine tablets are fully in stock in the 25mg, 50mg, 100mg and 200 mg doses.

So it may be a good idea to speak to your doctor about it. Because if a doctor writes a specific brand name on your prescription, the pharmacist must give you that specific brand. And lamotrigine is a category 2 epilepsy medicine. This means your doctor should talk through any changes with you and take into account how you feel before prescribing different versions of your epilepsy medicine.



Epilepsy Action Helpline Team

Submitted by rich on

I have been seizure free for 20 years by taking the USA version of Novartis TEGRETOL XR 400mg once a day. I am being forced to change Insurance company and the new Insurance does not pay Brand name medications, so I have been forced to find a solution due to the high price in USA (I tried generic 20 years ago and did not work). Now I am planing to buy the medication from a different country that I trust and they sell Novartis TEGRETOL, which in El Salvador is called TEGRETOL CR (for extended release), but the color and the layout of the tablet is different, however it is still Novartis.

I would trust more this option than a generic in USA. Do you have an opinion in my selection?

Submitted by Sergio on

Dear Sergio

I’m sorry to hear of your situation.

In the UK, epilepsy medicine is only available on a medical prescription.

It’s not advisable to buy your epilepsy medicine on-line. As the medical system in America is different to the UK, it would be best for you to contact the Epilepsy Foundation of America.  They may be able to help with your situation.



Epilepsy Action Helpline Team

Submitted by Diane-Epilepsy ... on

I hav3 had epilepsy for many years but thankfully have been seizure free for many years now.
My pharmacist started to change my phenobarbital to a different make so I went straight to GP to get the normal make put on the prescription
I still have to fight to get them to give me these .
I quote Epilepsy Associations words.
Why should I have to fight ?
I am strong but how many people are not speaking up.
I get told oh we only have a few of that make we have others!
It takes about 5 days to wait for a prescription.
I have made sure I am well informed so at least no one can say ah but to me!
Yes I could change pharmacist but live in a small village hut also why should I?
Advice - get very knowledgable

Submitted by Anne on

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