I also am unfamiliar with the migraine med (but since I have migraines too, maybe I should look it up
). I think the thought process on the switch from Imuran to 6mp is that since they are metabolized differently the body may use one more effectively than the other, so it is worth giving both a shot before giving up on the category entirely. Also, you don't say how long you have been on it, but keep in mind that you do need to give it at least 3 months, some say up to 6, to reach its full potential. A lot of us need to use it in combination with other medications as part of a regimen to keep things under control. I have used 6MP for over 13 years and been relatively stable, but I have had other drugs thrown in and out of the mix during that time.