This is something you'll have to discuss with your doctor. For Migraine and headache prevention, the recommended dosage is up to 100 mg twice a day, for a total of 200 mg per day. Some doctors will prescribe more if it is working and they think a higher dosage will be helpful.
Teri
PS: Just a point of information for you -- Typing in all caps on the Internet is considered shouting. Plus it's hard to read. :-)