Two separate issues. 

One has to do with bad prescribing practices (based on the fact that physicians get almost no education or training in substance misuse). That can--and should--be addressed at the provincial level, by educational facilities and the government appropriately monitoring prescribers.

The other has to do with smuggling, which is a federal problem, and extremely difficult--the tiniest imaginable amount of fentanyl/carfentanyl is lethal, and there's enough in a printer cartridge case to kill hundreds.