Thank you for your question and welcome to ADHDCentral.com. I am not very familiar with this medication (and I am not a health professional). I did do some searches but was unable to find very much information on using Topamax in order to get high.
Since this is a medication prescribed for migraine headaches, you might want to try asking your question on the migraine site at HealthCentral.
MyMigraineConnection
I am sorry I could not be of more help
Eileen