I have also been on topmax for about two years now for migranes. I cant remember crap, I have blurry vision, I am scattered, I dont have a sex drive at all and yes, my mouth is on fire as we speak. My mouth is always burning. Everything I eat seems to escalates the burning sensation. I've been to the dentist and the doctor and they have no clue. The dentist is the only one who mentioned that it could be a side affect from the medicine. He also mentioned it being extremely dry mouth and thought i should use biotene mouthwash and tooth paste. It did help a little for a while
Anyone can become allergic to medication overnight. Call or see your Dr. for a change in meds.