Metoclopramide
"Jim. 
 I've had migraines for over 60 years. Currently, they are frequent but not debilitating as in the past. I'm an anomaly, having migraines at my age (77). My doctor prescribed Reglan Pills with 6 hours between doses. Sometimes it helps, sometime not.  It's not my go-to Med but I use it because I don't want the others sometimes. 
I suspect high doses given quickly Can cause problems some have. Maybe my doctor, a stroke specialist who also has migraines, may be better informed than those prescribing high dose  quick injections. There are emergency  rooms in my area that I wouldn't let someone take me even with a heart attack. Remember, 50% of docs were in the bottom  1/2 of the class. You don't know where your doc was."