Dear Cam,
This is absurd AND way out of line. Please do NOT ask your doctor to choose one medication or the other for you. You have every right to use both, taking the proper precautions as you described, if you want to.
On the other hand, you might consier asking your doctor to prescribe Imitrex tablets instead of the Relpax, only because it would be more convenient for you. Your doctor could then tell you how to use the two of them, how many hours between a tablet and an injection, etc.
BUT, if the Relpax tablets are better for you than Imitrex tablets, don't let a pharmacist bully you. Your doctor is your doctor and does the prescribing. Your pharmacist, if acting professionally, should have called your doctor with any questions rather than putting you in that position. If I were in your place, I'd file a complaint with the state board that licenses pharmaciest. But, that's just me, and I can get cranky with stuff like this.
If you continue using Relpax and Imitrex, I see two ways you can go...
1) You can take the two prescriptions to two different pharmacies.
2) You can stick to principles and insist that they be filled at your current pharmacy.
If you go with the second option, which as a stubborn person, I would, think about going to the pharmacy or store manager with the problem.
I hope this helps, Cam! Please let us know how it goes?
Teri