Stef - before I went to an 'university' hospital for the surgery I was taking 125 mg of Topamax per day plus Trileptal. After surgery the epi there said that was not a sufficient or "normal" (my word, not hers.... I'm having memory/word problems this morning) dosage of Topamax and I slowly dropped Trileptal and went to 200 Topamax.
(Of course right now I'm quickly working Trileptal back in and have clonazepam on hand.)
Anyhow --- my epi said that 200 was the lowest standard dosage for an adult.
Good luck!!