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Side-effects and interactions

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

Do epilepsy medicines cause side-effects?

All medicines can cause side-effects, including epilepsy medicines. Side-effects are unwanted symptoms caused by medicines. When you get your prescription, it should, by law include a package leaflet which lists the possible side-effects.  The risk of getting side-effects varies from person to person.

Some people have told us that their side-effects have lessened over time, as their body has got used to taking their epilepsy medicines.

What should I do if I get side-effects?

If you have side-effects that continue, talk to your GP or epilepsy specialist. They might make changes to your epilepsy medicine to reduce the side-effects.

If you are driving or working with machinery, check the package leaflet to see if certain side-effects could make this unsafe for you.

The Yellow Card Scheme

Either you or your GP can report your side-effects to the Medicines and Healthcare products Regulatory Agency (MHRA) by using the Yellow Card Scheme. You can do this by:

  • Picking up a Yellow Card from your GP surgery or local pharmacy
  • Filling in a Yellow Card online.
  • Calling the Yellow Card freephone hotline: 0808 100 3352

Reporting side-effects to the MHRA can help make sure that medicines are made safer in the future.

Possible effects of epilepsy medicine on other things

Your bones

Some epilepsy medicines can affect bone health. Visit our page about osteoporosis and epilepsy to find out more.


Some epilepsy medicines make some types of contraception work less well than they should. And some types of contraception make lamotrigine work less effectively. Visit our section on contraception to find out more.

Possible effects of other things on epilepsy medicine

Medicines to treat other conditions

Some medicines used to treat conditions other than epilepsy can increase the risk of having seizures. They might lower your resistance to seizures. Or they may interact with your epilepsy medicines, making them work less well, or causing more side-effects.

If you are going to take any prescribed medicine or over-the-counter medicine, always check with your GP or pharmacist first. This is to make sure they won’t affect your epilepsy or treatment.

Below are some examples of these medicines. There are others.

  • Antidepressants
  • Benzodiazepines
  • Antipsychotics
  • Painkillers
  • Steroids


Some research suggests that eating grapefruit or drinking grapefruit juice could increase your chances of having unwanted side-effects from some epilepsy medicines. This is because a chemical that is naturally found in grapefruit can cause you to have higher levels of these medicines in your body. If you have any concerns about this, talk to your GP or pharmacist.

The medicines that can be affected by grapefruit are:

  • Carbamazepine
  • Diazepam
  • Midazolam

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.

Event Date: 
Wednesday 12 April 2017 - 11:11

Epilepsy Action would like to thank thank Dr John Paul Leach, consultant neurologist, 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 May 2017
    To be reviewed May 2020

Comments: read the 3 comments or add yours


My son is autistic, epileptic and mute. He has seizures every 21 days. He is on adjunctive therapy of Epilim and oxcabazepine. He can’t tell us about side effects, he is definitely sensitive to changes in type of `AED, quantity and manufacturer of the oxcabazepine. His neurologist feels side effects are overstated and unexpected seizures around a change in OXB form were not associated with the change. He is currently taking 300mg OXB from TEVA. This is now out of stock in the UK. Can anyone offer any advice

Submitted by Alan Hazlewood on

Hi Alan

It’s difficult when the neurologist sees things differently from you. Sometimes keeping a seizure diary can help to make your point about consistency of supply.

The MHRA guidance has put oxcarbazepine in category 2, meaning that the manufacturers’ version should only be changed after consultation with the patient or carer.

I have just contacted TEVA and although 300mg won’t be available till the end of December, there are 150mg tablets available.

You might also find our information on caring for someone with epilepsy and a learning disability useful. I do hope this helps a little.



Epilepsy Action Helpline Team

Submitted by Cherry-Epilepsy... on

Thanks for your reply Cherry. I knew that 150s werr available. In the summer theee was a shortage of 300s and we were advised to take the 600 version. Howver this produced two unexpected seizures. TEVA told me that the oxb as a chemical was made at same location and tabulated elsewhere at the normal location but the inactive ingredient level was different. They could not comment on the active ingredient level. So we are a bit reluctant to take a different format. On the otherhand local pharmacies claim TEVA is not necessarily stocked by the main distributer. What seems logical is to make a carefully managed switch to whoever is the most reliable manufacturer as there are several. Whilst you correctly mention the MRHA guideline the issue seems to be how to make it work all the way through the supply chain. Its my experience that pharmacists arent necessarily aware of it. I wonder if there is a centralised function of some sort that can help

Submitted by Alan Hazlewood on

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