You need a certain amount of medicine in your blood at all times. This way, when a seizure happens, your body is ready for it. Never skip a dose or stop taking your medicine without your healthcare provider knowing. Doing so could result in serious consequences. It's quite common for people with epilepsy to miss a single dose once in a while. Often, nothing bad happens, but your chance of having a seizure may be higher. Missing 1 dose is more likely to cause seizures if you're scheduled to take your medicine only once a day. Then, if you miss a dose, you've missed a full day of medicine. If you take it 2 to 4 times a day, the risk from missing 1 dose is less. But if you miss several doses in a row, the likelihood of a breakthrough seizure will be higher. So take all precautions to ensure that you take your medicine on time.
Ask your provider for written instructions on what to do if you miss a dose of medicine. Always check with your pharmacist about drug interactions before starting a new medicine or using any over-the-counter medicines, including vitamins, minerals, and supplements.