We hear about this from time to time. It seems like it's usually in Canada.
Have you explored options with the pharmacy/doctor, such as sumatriptan in vials, with syringes, so you can do it yourself, or the lower-dose autoinjector, Zembrance, which has plenty for stopping a CH attack? Or a triptan nasal spray?
Important info for when you get the Imitrex/Imigran: Extending imitrex - ClusterBuster Files - ClusterBusters
Some people get Imitrex prescription filled when they are out of cycle to stockpile it. It lasts a long time.