migraine prevention
"I can't begin to describe to you the kinds of nightmares that this medication gave me.  Believe me.  You don't want to know about them.  It DID, however, prevent a migraine that would have most certainly occurred.  (It rained one day and weather changes are my biggest trigger.)  Yes, this medicine worked for me in the sense that it prevented a migraine. BUT!!!  I would rather treat an existing migraine than have these TERRIFYING dreams every night."