You asked when to take the preventative Topamax. As a preventative, you take it every day, at the strength your doctor prescribes. And do not stop, even if you feel better. You'll feel better because of the medicine. My Neurologist prescribed my Topamax at a low dose, one at bedtime. And I still had more than 2 or 3 migraines per week. So he upped the Topamax to one 100 mg at bedtime, and I've been mostly better for a number of years. I tried Depakote first, but I had a daily headache, stomach ache, and muscle aches, so I got off of it fast.View Thread