Mary,
Could you be talking about DHE? I don't know of any medication called GHE. DHE (dihydroergotamine) is sometimes used to break a Migraine. There are several medications that can be used in IV infusion for a Migraine that's not responding to medications. You can find more information, including a list of these medications, in IV Treatment of Refractory Migraines.
Hope this helps,
Teri