Wow -400 a day is a lot!!

Google side effects of meds to find some sites. i think there are a few I went to where I read patient stories and reviews.

Tingling in your hands and feet may occur as your dose increases. You may also get diarrhea, some have had to lower their dose or go off Topamax completely because of that side effect. it makes a lot of drinks taste strange. I have also lost my desire for alcohol and drink very sparingly. There is supposed to be some weight loss with it, but I was kind of small to start with...I can tell you that it didn't cause me any weight gain.

i take 200 mg. 100 in the morning and 100 at night. When I tried to go higher than that I had a lot of trouble with my stomach.

Good luck, Sandy