Propranolol
is an FAA "approved" medication. Your AME has to do a hypertension evaluation though. Imitrex, Axert, Maxalt, and Zomig are approved for migraine treatment as well. The big, bad tranquilizing cocktails like Midrin are not approved. The problem is, those drugs approved specifically for migraines work by constricting blood vessels, which may not right for you if you have systemic hypertension. The fact that you're on Propranolol tells me that you might. In addition, you'd be moving from a preventive drug, to an interventional/migraine arresting type drug. If you don't have hypertension, I'd recommend talking to your physician about trying to not take anything for a while. You may never have another migraine, or you might have one in 3 days. Whatever you decide to do, just be mentally prepared that your medical may get hung up for a while in Oke City. Join
AOPA if you haven't already (they can be great advocates for Joe Bob Pilot)!

Their medical people can definitely help your medical process go smoother. Good luck!