No idea Linda. But I am also perscribed to relpax (40mg). If I am experiencing a very bad migraine I take the imitrex. If it's just one of those migraines that stays at a low grade level but isn't going away on its own, I take the relpax because it is not as strong as imitrex (for me anyway). You cannot mix these medications!! But I alternate them so I don't get rebounds. I understand wanting to cut the imitrex...it's really powerful and affective but if your headache isn't that bad you don't want to waste them.