Banning Cocaine? How is this going to work if the adjacent state doesn't? I point out to you how this same idea is working in New York as regarding their cigarette taxes.
It isn't.
Beyond that, it ignores the fact that much if not most drug production involves foreign nations, which is the sole domain of the Federal government.
And I point you to Article V of the US Constitution, which specifies the process of amendment. This is the means by which the States modify the enumerated powers transferred to the national government.