Side effects and interactions

Epilepsy medicines can cause different side effects, and may interact with other medicines or certain foods.

If you have problems or questions, your doctor or epilepsy nurse can help.

Do epilepsy medicines cause side effects?

When you get your medicine it will include a patient information leaflet that lists the possible side effects. Side effects are unwanted symptoms caused by medicines. All medicines can cause side effects, including epilepsy medicines. The risk of getting side effects varies from person to person.

Some people find their side effects lessen over time, as their body gets 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.

Bone health

One side effect of epilepsy medicines to be aware of is that they can affect bone health, when taken for a long time. Visit our page about osteoporosis and epilepsy to find out more.

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: 0800 731 6789

Reporting side effects to the MHRA can help them identify any new side effects or safety issues they might not have known about.

Examples of interactions

Epilepsy medicines can sometimes affect, or be affected by, other medicines and drugs. When this happens it is called an interaction. Interactions can also happen with certain foods, drinks, supplements and complementary treatment.

  • Contraceptives

    Some epilepsy medicines make some types of hormonal contraception, such as the pill, work less well than they should. This could mean you have an unplanned pregnancy.

    Some types of contraception make the epilepsy medicine lamotrigine work less effectively. This could lead to an increase in your seizures.

    Visit our section on contraception to find out more.

  • 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, over-the-counter medicine or herbal remedy, always check with your GP or pharmacist first. This is to make sure they won’t affect your epilepsy or treatment.

  • Grapefruit

    It’s important to avoid eating grapefruit or drinking grapefruit juice when taking some epilepsy medicines. This is because a chemical that is naturally found in grapefruit can increase the levels of these medicines in your body. This could increase your chance of having side effects.

    The medicines that can be affected by grapefruit are:

    • Carbamazepine
    • Diazepam
    • Midazolam
Published: April 2022
Last modified: April 2024
To be reviewed: October 2023
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