St. John's wort interferes with epilepsy drugs
Publication Date:07/11/2007
Introduction
St John's wort, a popular herbal remedy for depression, can stop epilepsy drugs from working properly, the UK's drug safety watchdog has warned.
What do we know already?
St. John's wort is a herbal remedy for depression. It's not a treatment that doctors usually recommend, but there's some research suggesting it can help people with mild or moderate depression.
Although some people see herbal treatments as a more natural alternative to conventional medicine, these remedies aren't without side effects. The biggest problem with St. John's wort is that it can interfere with the effects of other medicines.
What does the new report say?
An announcement from the UK's drug safety watchdog has warned that St. John's wort could stop epilepsy drugs working properly. One patient started to have more severe epileptic seizures, and also to have them more often, after taking St. John's wort together with their epilepsy medicine.
Doctors already knew that St. John's wort could react with some epilepsy drugs, such as carbamazepine. But the warning has now been extended to cover all the drugs used for epilepsy.
Where does the report come from?
The warning comes from the Medicines and Healthcare products Regulatory Agency (MHRA). The MHRA is the organisation that monitors the safety of drugs in the UK.
What does this mean for me?
If you're being treated for epilepsy, you shouldn't take St. John's wort. If you think you may have depression, make an appointment to see your doctor. He or she will help you find a safer treatment.
For anyone not taking other medicines, St. John's wort doesn't seem to cause many side effects when taken at normal doses for a few months. However, St. John's wort can react with lots of medicines, not just epilepsy drugs. Some of the most common are:
- The contraceptive pill
- Warfarin, and similar drugs used to stop your blood clotting
- Antidepressants
- HIV drugs
- Migraine drugs
- Simvastatin, which is used to treat high cholesterol.
These are just a few examples. St. John's wort can interfere with lots of medicines, so check with your doctor or pharmacist if you're thinking about taking it.
Another problem with St. John's wort is that it's sold as a supplement, not as a medicine. This means it's not tested for quality in the same way as medicines. St. John's wort contains several chemicals, and the amount of these can vary between brands. Even if the amount of one of these chemicals is standardised in a particular brand, the others might not be. It can be hard to know exactly what you're buying.
What should I do now?
If you're thinking of taking herbal remedies, it's always a good idea to check with a doctor or pharmacist. They'll be able to advise on taking them safely, and make sure you're not missing out on more effective treatments.
If you're already using St. John's wort at the same time as other medicines, talk to your doctor before you stop taking it. Stopping St. John's wort can increase the effects of your other medicines, which may be harmful.
If you think that a herbal remedy or conventional medicine you are taking has caused an unwanted side effect, you can report it either to your doctor, or to the drug safety watchdog, the MHRA. The MHRA can then issue new drug safety advice, on the basis of these reports. For more information, go to www.yellowcard.gov.uk
From:
From: Medicines and Healthcare products Regulatory Agency. Drug Safety Update: Volume 1, Issue 4, November 2007. Available at: http://www.mhra.gov.uk (accessed on 5 November 2007).
To read more about St. John's wort, see our information on depression.
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© BMJ Publishing Group Limited ("BMJ Group") 2007. All rights reserved
This information does not replace medical advice. If you are concerned you might have a medical problem please ask your Boots pharmacy team in your local Boots store, or see your doctor.
