DO NOT take anything with DM . If you have a good relationship with your pharmacy you are perfectly allowed to ask if a medicine you take would interfere with cold meds and vice versa. If given the name of OTC then ask how does this affect my seizures? You can also ask what is safe for me to take?
Keep a notebook of questions like this and make sure at your next appointment you ask all possible what if questions.

Ask your pharmacist about drug interactions, they have data bases they can consult to see if there is a problem. Each epilepsy drug is different so the question is really about your specific drug

I can only speak for myself, and that i can't take any cold/flu medicines at all. The last time i did i had 3 seizures in one night and it forced me to take the next day off to recover. It depends on the cold/flu medicine and what is in it. Every year manufactures are making them stronger so you can bounce back the next day. The question is, how will it affect the meds you are taking now? I don't think there is cold a medicine that will not affect your seizure meds due to how strong they are making them now. I have heard of a neighbor had to be taken to emergency because of how cold/flu medicine wiped out their heart meds. Talk to your neurologist first.

I had no idea that they even lowered seizure... Threshold???

Thank you Wcrout :) very helpful info to know :)