We exist to improve the lives
of everyone affected by epilepsy

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 it is important that you get the same version of your epilepsy medicine, every time you pick up a prescription.

Generic prescribing

Nearly all medicines have a generic name and a brand name. The generic name is usually 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 is available for patients, it is under licence. This means that only the company that developed it can sell it. They will give it their own brand name. Once the licence runs out, any company can make the medicine, giving it a different brand name. The generic name stays the same.

Here are the generic and some brand names of some commonly used epilepsy medicines.

Generic name

Brand names







sodium valproate




If a doctor writes the generic name of your medicine on your prescription, a pharmacist can give you any brand of that medicine. This is called generic prescribing. To keep costs down, a pharmacist may choose to give you a cheaper version of a medicine.

Parallel imports

Some companies make the same medicine at factories in the UK and in several other countries. An example of this is the epilepsy medicine Tegretol, which is made in Italy and the Netherlands, as well as in the UK. Some chemists in the UK carry supplies of Tegretol from all three countries. So, if a pharmacist gives you Tegretol, it could have been made in any of those countries.

When medicines that are made in the UK are also imported from other countries for use in the UK, they are called parallel imports. There are a number of signs that your epilepsy medicine is a parallel import. For example, the packet may look different or have wording in another language.

The problem with generic prescribing and parallel imports

Generic prescribing and parallel imports mean there can be many different versions of one medicine.

Some people, who have switched to a different version of their epilepsy medicine, have noticed that they have had more, or different, seizures. Some people have also experienced side-effects that they have not had before.

For this reason, Epilepsy Action believes that people with epilepsy should always get the same version of their epilepsy medicine, wherever possible. This is called consistency of supply. However, not all doctors agree with this.

Advice for people who prescribe epilepsy medicine

The National Institute for Health and Care Excellence (NICE) is an independent organisation. They provide guidelines for treatment and care for people using the NHS in England, Northern Ireland and Wales.

NICE’s advice about prescribing epilepsy medicines

Consistent supply to the child, young person or adult with epilepsy of a particular manufacturer's AED [epilepsy medicine] preparation is recommended, unless the prescriber, in consultation with the child, young person, adult and their family and/or carers as appropriate, considers that this is not a concern.

The Medicines and Healthcare Products Regulatory Agency (MHRA) also gives guidance to people who prescribe medicine and to pharmacists. It is not official policy that must be followed, and Epilepsy Action does have some concerns about it.

The MHRA’s advice about prescribing epilepsy medicines

Category 1 – Phenytoin, carbamazepine, phenobarbital, primidone
For these drugs, doctors are advised to ensure that their patient is maintained on a specific manufacturer’s product.

Category 2 – Valproate, lamotrigine, perampanel, retigabine, rufinamide, clobazam, clonazepam, oxcarbazepine, eslicarbazepine, zonisamide, topiramate
For these drugs the need for continued supply of a particular manufacturer’s product should be based on clinical judgement and consultation with patient and/or carer taking into account factors such as seizure frequency and treatment history.

Category 3 - Levetiracetam, lacosamide, tiagabine, gabapentin, pregabalin, ethosuximide, vigabatrin
For these drugs it is usually unnecessary to ensure that patients are maintained on a specific manufacturer’s product unless there are specific concerns such as patient anxiety, and risk of confusion or dosing errors.

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. If the brand is written on your prescription, the pharmacist must give you that specific brand, by law.

If your take an epilepsy medicine that is in category 2 or 3 of the MHRA guidelines, your doctor might not want to prescribe you the same brand. However, you could ask your doctor if you could stay on the same version if:

  • The thought of changing makes you feel anxious or confused, or

  • You think you have had side-effects or seizures because you have been prescribed a different version of your epilepsy medicine

You can ask your doctor to write ‘no parallel imports’ on your prescription, but the pharmacist doesn’t have to take any notice of this. However, you can insist that your epilepsy medicine is given to you with a Patient Information Leaflet and packaging that is written in English.

If your epilepsy medicine is not made in the UK, it may be impossible to get exactly the same version every time. It is advisable to discuss this with your GP (family doctor).

Reporting problems with epilepsy medicines

If you think that you are getting side-effects from your epilepsy medicine, or they have caused your epilepsy to change, talk to your GP (family doctor). They can report these issues to the Medicines and Healthcare products Regulatory Agency (MHRA).

You can also report side-effects yourself by completing a Yellow Card. These are available from your GP (family doctor), pharmacist or the Yellow Card scheme:
Tel: 0808 100 3352
Website: yellowcard.mhra.gov.uk

Epilepsy Action encourages you to use the Yellow Card scheme. This is especially important if you think that having the version of your epilepsy medicine changed might have caused any of the following:

  • A breakthrough seizure
  • Different seizures
  • Worse or more frequent seizures or
  • Worse side-effects

Please include details of the original version and the new version of your epilepsy medicine.

This is so the MHRA can make changes to their guidance about prescribing epilepsy medicines, if necessary.

Pay it forward

This resource is freely available as part of Epilepsy Action’s commitment to improving life for all those affected by epilepsy.

On average it costs £414 to produce an advice and information page – if you have valued using this resource, please text FUTURE to 70500 to donate £3 towards the cost of our future work. Terms and conditions. Thank you

We can provide references and information on the source material we use to write our epilepsy advice and information pages. Please contact our Epilepsy Helpline by email at helpline@epilepsy.org.uk.

Epilepsy Action would like to thank Professor Markus Reuber, Professor of Clinical Neurology at the University of Sheffield and Honorary Consultant Neurologist at the Sheffield Teaching Hospitals NHS Foundation Trust for his help in producing this information.

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

  • Updated January 2014
    To be reviewed January 2017

Comments: read the 6 comments or add yours


My husband has been on Carbagen now for 3 1/2 weeks and has been really ill constant tiredness feeling sick light headed constapaited having trouble passing urine. GP said contact consultant, no joy there given a 3 month appointment and we up the dose to 400mg morning and evening next week, is this all normal and reading have we/he being given the cheaper version ( which has happened with other tablets) he is waiting for Kidney stone op's and should have had them done but had to be put back due to having two night seizures 3 months apart ( hoping its the stones causing them and ok once he has op) any information would be great.
thank you

Submitted by Alison Wilson on

Hi Alison

Thanks for your message. It sounds like a very tough time for your husband right now. What you are describing could be side effects of the Carbagen (Carbamazepine). And although very rare, carbamazepine has been known to affect liver and kidney function. So it would be a good idea to talk with a doctor about what is going on. You might be able to get a faster appointment with the support of your GP.  Another possibility is to consult with an epilepsy specialist nurse. The hospital where he is seen will be able to tell you if they have any epilepsy specialist nurses.

I hope things begin to improve soon.


Advice & Information Team

Submitted by Sacha-Epilepsy ... on

I have been taking Tegretol Retard 600mg (200 & 400mg) twice daily for about 30 years along with Clobozam. Recently changed to Co-operative Pharmacy from Boots has better service. However noticed info re parallel imports and one of boxes of last prescription states "There are two different batches of the same medication in this container. The size, shape colour or markings may vary." No Patient Information Leaflet In it (there are in the others) as far as I can see. The two batches have different packaging, and PL holders are different. One of the batches has spelt carbamazepine without the last "e". Should I be concerned?

Submitted by Catherine Madge on

Hello Catherine

Thank you for your message. Consistency of supply can be a big issue for many people. I hope this information helps.

We strongly believe people with epilepsy should receive the same version of their epilepsy medicines whenever they get a repeat prescription, unless their clinician prescribes otherwise. It should be from the same manufacturer, and from the same country. This applies to generic versions, ‘branded’ generics and for brand leaders.

From what you have said, it does sound like you have received some parallel import medicine. For many people this can cause problems. We also have concerns about people getting mixed batches, as they may also cause problems. If you are concerned, it would be a good idea to return and speak with your pharmacist. You should try to receive the exact medicine you were receiving before, to avoid any potential problems. Incidentally, carbamazepin is the German spelling of carbamazepine. You are supposed to receive a patient information leaflet with your medicine. It should state where the medicine is manufactured.

It’s also a good idea to ask your doctor to write ‘no parallel imports’ on your prescription. The pharmacist doesn’t have to take any notice of this. But, you can insist that your epilepsy medicine is given to you with a Patient Information Leaflet and packaging that is written in English.

Advice &  Information Team

Submitted by Sacha-Epilepsy ... on

Hello, I have been taking Tegretol 600mg twice a day for 35years. And, for the last 2 years I have also been having Keppra 500mg twice a day. To begin with, the Keppra did not give me any side effects to speak of but over the past year I have experienced periods of double-vision, anxiety, and feeling spaced out. However, I have been ok (no side effects) when taking certain batches of these medications. UCB manufacture the Keppra, and, Novartis the Tegretol. My question is can different batches by the same manufacturers give me side effects and others not? I have an appointment with my GP soon and I would appreciate your views on this. Thank you. David

Submitted by David on

Hi David

As you may have seen from the web page, we do advise people to stay with exactly the same version of their epilepsy medicine wherever possible.

For some people switching versions will be no problem at all, but for others it can risk you having a breakthrough seizure.

The easier thing to be aware of is to make sure you don’t switch from branded (Keppra, Tegretol) to generic (levetiracetam, carbamazepine), or the other way round. If you are on the branded versions, then as long as your doctor writes the branded name on your prescription, that is what your pharmacist will have to give you.

The more difficult thing is to see if your medicine is a parallel import. This is when it is made by the same manufacturer, but physically made and packaged in a different place, usually within Europe. The clearest clues to this are a foreign language on the box and possibly a different colour. So even a parallel import can be a slightly different version of the medicine.

The Medicines and Healthcare Products Regulatory Agency (MHRA) regulate everything to do with medicine. They and the drug companies do this based partly on feedback through the Yellow Card scheme. So it would be really useful if you felt able to report your side effects using this system.

I do hope this answers your question. But If we can be of any more help, please feel free to contact us again, either by email or the Epilepsy Helpline freephone 0808 800 5050.


Epilepsy Action Advice and Information Team

Submitted by Cherry, Epileps... on

Contact Author

This question is for testing whether you are a human visitor and to prevent automated spam submissions.
By submitting this form, you accept the Mollom privacy policy.