Answer by Nicholas Poolos, M.D.
I hear this question frequently in clinic. The only clear answer to this question is that alcohol and epilepsy don’t mix well. Consuming large amounts of alcohol raises the risk of a withdrawal seizure as blood alcohol levels decline following drinking. We know that people without epilepsy can provoke a seizure just from alcohol withdrawal, and for people with epilepsy, the risks are even higher.
Another risk of drinking is that if alcohol intake occurs on a consistent daily basis, the liver increases its metabolism to compensate, and metabolizes many antiepileptic drugs faster too, lowering their blood levels. This doesn’t mean that people with epilepsy have to completely avoid alcohol, but I suggest they use great caution, no more than a drink or so at a time, and only on an infrequent basis.
As for coffee–or rather the caffeine in coffee, tea, and soda–some researchers have reported that caffeine could make seizures more likely. This is because caffeine is a mild stimulant. I don’t think there’s strong evidence for this, but as for all things, keeping caffeine intake moderate is a good idea.
However, more dangerous stimulants can turn up in unexpected places, such as herbal supplements advertised for ‘energy’ or ‘weight-loss'; these often contain substances known to provoke seizures, such as kava kava, bitter orange, or ephedra, and should be avoided. (In general, if you’re taking any kind of herbal supplement, always discuss it with your physician.) And it goes without saying that illegal stimulant drugs such as methamphetamine or cocaine will provoke seizures.
Finally, on the subject of foods that might affect epilepsy or antiepileptic drugs, grapefruit juice is known to inhibit the metabolism of a number of drugs, including possibly carbamazepine (Tegretol)–but I think you’d have to drink a lot of it to experience any effects.