Switching between different versions of epilepsy medicine

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.

Branded medicines

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.

Generic medicines

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.

An example

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:

Epilepsy medicine

Advice

Category 1

  • Carbamazepine
  • Phenobarbital
  • Phenytoin
  • Primidone

 

If you take one of these medicines, your doctor should make sure you stay on the same version.

Category 2

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

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.

Category 3

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

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)

Website: yellowcard.mhra.gov.uk 

 

If you would like to see where our information is from, download a copy of this information with references

Code: 
F051.11

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 2020
    To be reviewed December 2023

Comments: read the 9 comments or add yours

Comments

I have been on ethosuximide for the past 15 years along with a multitude of other medications. Only now my regular pharmacist are saying they can not get hold of it due to manufacturing problems. DR’S are unaware of any problems with this medication so gave me another prescription to take to a different pharmacy. I have now got ethosuximide but from a totally different make one that I have never seen before. I don’t do well with change. My epilepsy can not be fully controlled, and to now change a major medicine I’m worrying that my seizures will increase dramatically.

Submitted by Lauren

Dear Lauren

 

It’s a worrying time when you’re told your epilepsy medicine isn’t available.

 

As we are not aware of any manufacturing problems with ethosuximide, could you please tell us the name of the manufacture of your usual ethosuximide. We can then look into this for you.  

You can either email helpline@epilepsy.org.uk or phone the Epilepsy Action Helpline freephone 0808 800 5050. Our helpline is open Monday to Thursday 8.30am until 8.00pm, Friday 8.30am until 4.30pm and Saturday 10.00am until 4.00pm.

 

Regards

 

Diane

Epilepsy Action Helpline Team

Submitted by Diane - Epileps...

Has anyone had a problem with their GP refusing to write a particular brand name on their prescription? My daughter has been on Keppra (UCB Pharma brand) and Lamotrigine by Lamictal. Her GP has said that due to the cost, they are no longer going to specify these brands and that she will have to have the generic brands. She has been on the main brands for 6-7 years with no problems or side effects. Her neurologist said three years ago at an annual appointment that she should stay in these brands as changing to a different brand could cause breakthrough seizures or side effects. The GP wants a letter from the neurologist to confirm this, but he has since left the hospital. If I can't provide proof and the GP won't give a prescription with these brands on it, is there anything I can do? My daughter is on the autistic spectrum and is getting stressed out worrying about it.

Submitted by Jenny C

Hi Jenny –some GP services are being advised to make savings by prescribing generic rather than branded medicines.  The MHRA advice about swapping epilepsy medicines is for guidance. So it isn’t something prescribers have to do but they should take notice of it. You’d be welcome to take our information to talk through with your surgery if you think that might help.  

It can be a worry when in the past consultants have advised a particular brand of epilepsy medicine. But generic makes of epilepsy medicines are well regulated and contain the same active ingredients as the brand medicine.

We know that many people change between brands without an increase in side effects or seizures. You may be able to reassure your daughter a little with this information. It could be worth keeping a diary of any changes or seizures that you notice though so that you can monitor things and go back to your GP if you need to.

If you want to talk any of this over you’d be welcome to call us on the Helpline.

Regards

Mags

Epilepsy Action Helpline Team

Submitted by Mags - Epilepsy...

I’ve recently moved house and have changed doctors.
I’m now in GP only care, but when I was under the epilepsy nurse, they were at pains in the past to say that I must only have branded Keppra not generic.
I went to collect my first script from my new pharmacy today where they tried to give me the generic version. I refused and handed it back.
I can understand that they’re wanting to make the (massive) cost saving, but why has my epilepsy nurse practitioner been insistent on not having generic?
I’m seizure free, I drive and although the number showing increased seizure activity when switched is low. I really don’t want to take the risk.
I’m now being bounced between the doctor and the pharmacy - each blaming the other for the change.
Can you give me any advice / reassurance please?

Submitted by Jon F

Hi Jon – This must be worrying for you. We know that some GP services are being asked to make savings by prescribing generic rather than branded epilepsy medicines. And we have spoken to people who are experiencing this. But I’m not sure why your nurse said you should always have Keppra brand of levetiracetam. Generally if it is important that someone stays on the same brand of epilepsy medicine this brand is put on the prescription.

 

It’s tricky because some people can change between different brands of their epilepsy medicines without any problems but some people notice changes. And as you say there can be risks and worries about doing this.  

 

The MHRA information about swapping medicines is for guidance. So although it isn’t something prescribers have to follow they should take notice of it. You’d be welcome to use our information to talk through your concerns with your surgery. It might also be a good idea to keep a diary so that you can note and report any changes to your doctor.

 

If you want to talk any of this over you’d be welcome to call us on the Helpline.

 

Regards

Mags

Epilepsy Action Helpline Team

Submitted by Mags - Epilepsy...

I reside in the U.S. My son has had epilepsy since he was 11 yrs old, beginning with small absence seizures of which I was unaware, but progressed to a grand mal which got him into treatment. He is now 45 yrs, and lives in another state, far from me. Initially, his neuro put him on Carbemazaprine and phenobarbital. After adjusting the dosage, he was well controlled, except that he was terrible about taking his meds consistently, when and how he should. Nonetheless, he remained seizure free for the requisite time and got his driving license at 16.

For a time after he moved out, married, etc., he did well. Then he gained quite a bit of weight, and developed type ll diabetes. His epilepsy meds were adjusted and Keppra was added, because he had several breakthrough seizures within a few weeks time. He was getting a generic, and dr. Changed to require brand. He lost the weight, was seizure free for a while, until last year. Now he has had several within a few months of each other, and of course, surrendered his license. They have just completed an in hospital test which involved hooking him up to electrodes to monitor brain activity, taking him off meds, and depriving him of sleep. He had to stay in bed for five days to complete this test. Now the epileptologist is offering VNS and continue Keppra, Vimpat, and Zonisimide. I found your website while researching the surgical option, and have found it incredibly helpful and informative. Thank you for this great source. I will also look up the Epilepsy Association in the U.S.

Submitted by Marion McGrath

I sometimes have issues with trying to stick to the same brand of my Medication which is Lamotrigine. My nurse suggests I must stick to the same brand that is in stock. It doesn't matter which one too much, but if there isn't enough of one that I must stick to, then what do I have to do? I am trying to find more information about this issue but unfortunately, I am having no luck.

Submitted by Thomas George R...
Dear Thomas
 
Thank you for your message. 

As you can see from our website information lamotrigine is in Category 2 medicine. This means that your doctor should use their clinical judgement and consult you when deciding whether you need to stay on the same version. 

I'm unsure from your message about what your nurse meant when they said that you must stick to the same brand that is in stock. And that it doesn't matter which one too much. 
Because we are not medically trained we are not able to give you medical advice. It sounds like it might be worth getting in touch with your nurse to ask for some clarification?


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.

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. For most people, it is safer to take a different version of their medicine than to run out and stop taking medicine suddenly.

I hope this information helps. But if we can be of any more help, please feel free to contact us again, either by email or the Epilepsy Action Helpline freephone 0808 800 5050. Our helpline is open Monday to Thursday 8.30am until 7.00pm, Friday 8.30am until 4.30pm and Saturday 10.00am until 4.00pm.

Regards

Tove
Helpline Team
Submitted by Tove - Epilepsy...

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