Cyproheptadine
"My son was only 4 when he was diagnosed with cluster migraines.  The diagnosis came after a year because they rarely occur in children that young.  The horror of hearing him scream "Mommy help me!  Help me!  Why does my head hurt!!" broke my heart.  Our pediarician recommended a drug that controls seizures but sometimes actually causes seizures. Nope was my answer. Next he recommended Periactin. With little side effects and my sons headaches cycling one per day for 4 days I agreed.  It was the best decision we ever made.  As long as he takes his med he has no headaches at all.  It has been the best blessing ever and given him a normal pain free life!!!!"