I have chronic migraine, and the only prophylactic medications that have ever worked for me are sansert (no longer available in US) and methergine, which dulls the pain and limits other problems like nausea. I've tried to taper off the methergine, but recently (last May) discovered that I apparently need the vasoconstricting effect. I had been taking 1/day and went back to 4. Now my pharmacy has raised the price of methergine, and it will be costing $1200/month until I get out of the Medicare doughnut( hole. Is there anything (vasoconstrictor?) I can substitute for the methergine?