In general Excerine does it for me, if I catch it in time.. I see floaters or flashy lights about 20-30 minutes before. Do you get any warning signs like that?
If I miss it, I'm screwed. Recently I had one last for a week. That sucked. Doc gave me some big guns to knock that out.
I haven't tried Topamax, but why not give it a shot? If it messes with you, you can stop... and there's a chance it'll help you out and make then never happen again. *shrug* Wikiepdia has stats on the percentage occurrence of side effects...
Topiramate - Wikipedia, the free encyclopedia. It's not low by any stretch of the imagination, but it's not like a 90% chance.