I've been taking topomax (the generic equivalent) for 10-15 years now. I started on 25 mg and worked my way up to 200 mg twice a day. I simply take one in the morning when I get up and one at night before bed. My schedule is very erratic, so there are days when I take the meds 10 hrs apart and others when I take it 14 -16 hrs apart. Changing the times has not seemed to affect the effectiveness at all.
The only side effect I've ever had is what I refer to as "Topomax brain" (and others I know that are on it also use the term) - short term memory loss, especially when you completely forget a word, i.e. it was "right on the tip of your tongue".
Hope this info helps!