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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 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

It is especially important to report any side-effects or seizures that you think have happened as a result of changing the 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


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 2 comments or add yours


I have been taking TEGRETOL (alongside two other anti-convulsants) for about 25 years, with no problems. In January 2013 I was prescribed carbamazepine as normal by my GP but when I collected the medication from my pharmacist, I was given CARBAGEN. It is, like Tegretol, a variant of carbamazepine but I am in no doubt at all that it had a negative effect on me within a few days - specifically, I had a grand-mal seizure. This has never happened at any previous time when I have been taking my medication correctly. Having read the above article, it only confirms my earlier suspicions that Carbagen is/was incompatible with my neurological needs; I have spoken at length with my GP about it but he - probably correctly - denied responsibility or liability because the prescription only ever specifies carbamazepine and not any particular brand. It leaves me with no other conclusion to draw than the pharmacist - who I have been getting my medication from for about 12 years - was negligent and in all probability was looking to cut costs at the potential risk of physical harm to customers.

Submitted by Jack on

Hi Jack

Thank you for your question.

Epilepsy Action and some professionals believe that taking a different version of epilepsy medicines can affect your epilepsy. However, there is conflicting evidence and more research is needed.  This means, at present, a pharmacy can prescribe a generic or parallel import if the GP writes carbamazepine on the prescription.

If you haven’t already, you may wish to report your suspected side-effect of taking carbagen. You, or your doctor, can report this to  the Medicines and Healthcare Products Regulatory Agency (MHRA), using the Yellow Card Scheme. The MHRA Yellow Card reports are evaluated each week to find possible previously unidentified hazards and other new information on the side effects of medicines. When an new possible side-effect is identify, the MHRA carefully consider the information and re-evaluate the situation.

As explained on our webpage, the best way to get the same version of your medicine is to ask your doctor to prescribe it by brand name. The law says that if the brand is written on your prescription, the pharmacist must give you that specific brand. If you are already taking a medicine without a brand name, and are happy with it, you could ask your doctor to write the name of the drug company and medicine name, on your prescription. You can ask your doctor to write ‘no parallel imports’ on your prescription, but your pharmacist doesn’t have to take any notice of this. However, many pharmacies will do their best to help their customers, so it may still be worth asking your doctor to do this.

Advice and information

Submitted by Diane on

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