When do you find benefit in sequencing different dopamine receptor blockers for emergency treatment of migraine?

I know that these medications given intravenously have been found effective abortively in randomized, double-blinded, placebo-controlled trials. Prior to the advent of the triptans in the early nineties, I often treated migraine headaches abortively with metoclopramide 10 mg orally, in 15 minutes, f...

Prochlorperazine has the strongest evidence of efficacy for IV acute treatment of migraine disorder. I have not routinely switched to metoclopramide IV if prochlorperazine was not effective. I am not aware of specific studies to guide this answer.

We do switch treatments within the same class when i...