How do you perk yourself up when you’re feeling sleepy? Many people choose a strong cup of coffee, while others go for tea - or perhaps a caffeinated soda. Caffeine is available in many drinks, can be taken in pills and is even found in chocolate, and it is the most widely-consumed psychoactive substance (drug) in the world. Billions of people take it in some form every day. But can caffeine trigger seizures in people with epilepsy? 

If you (or someone you know) have epilepsy, you might know that seizures happen when there are repeated abnormal bursts of electrical activity in the brain. Caffeine is known to make the brain more ‘excitable’. This means there might be a risk of caffeine seizures. Let’s find out about possible links between epilepsy and caffeine.

Not just coffee

When they think about caffeine, most people think of a cup of coffee. But it’s also important to remember it’s present in many other foods and drinks too. If you’ve noticed caffeine seems to affect your seizures, remember to check the ingredients list of drinks to find out if they contain caffeine. Some of the most common sources of caffeine include:

• Coffee
• Black tea
• Green tea
• Cola
• Most energy drinks
• Chocolate
• Drinks containing guarana
• Additives such as taurine, ginseng, kola nut and more
• Some supplements

What are the risks around seizures and caffeine?

At present, researchers do not definitely know whether consuming caffeine makes it more likely that people with epilepsy will have seizures or not. There have not been enough studies on seizures and caffeine to draw definitive conclusions. Always check with your doctor for advice personalized to you about consuming caffeine.  

Research has highlighted some of the possible issues associated with caffeine and epilepsy:

• Very large amounts of caffeine could be a problem: There have been a few case studies where individuals with epilepsy were consuming very large amounts of caffeine (for example, several liters in a week). In these cases, those people had fewer seizures when they reduced the amount they were consuming. This suggests there could be a relationship between epileptic seizures and consuming large quantities of caffeine. But these are not based on large or strong clinical studies, rather on unusual examples of people who consumed much more than normal.
• Seizures and caffeine withdrawal: It is possible that caffeine withdrawal (where you stop drinking coffee or caffeinated soda) might be a seizure trigger for people who take caffeine regularly.
• Caffeine could protect against seizures: It might sound surprising, but some studies of epilepsy and caffeine with animals found that regularly taking low doses of caffeine might actually increase the seizure threshold (which suggests it could make it less likely that seizures will happen). That said, the results of different studies aren’t all consistent, and experiments with animals don’t necessarily translate to humans.‍
• May depend on the individual: Different people process caffeine in different ways. Some people process it very quickly, while it might take hours for others. This could also affect how it interacts with anti-seizure medications or your sleep patterns (if caffeine keeps you awake at night, that might also trigger tiredness seizures).

Speak with your doctor about your caffeine consumption and how it may affect your epilepsy. 

‍Seizures and other drugs: Learn about epilepsy and alcohol

Coffee and seizure medicine

If you take anti seizure medicines (ASMs) to control your seizures, it is important to find out whether caffeine might ‘interact’ with your medication. At present, there isn’t definitive evidence to say whether normal doses of caffeine can make ASMs less effective, but there is a potential risk here. Ask your doctor for more information.

A 2023 article in a scientific journal reported that some small experiments with animals have found caffeine reduces the anticonvulsant effects of many ASMs. This could mean people are more likely to have breakthrough seizures. However, the data here is mixed and other large clinical trials didn’t find a negative effect of caffeine on ASMs.

When you’re taking ASMs, it’s important to talk with your doctor about the medicine’s possible interactions - especially if you drink caffeinated drinks. Together with your doctor, you can plan for the potential risks.