A nurse practitioner, according to the Controlled Drugs and Substances Act, can prescribe controlled drugs if it is allowed on-reserve, if the nurse practitioner is working on-reserve or for the federal government, and if it is allowed by the province.
So, for example, in Ontario, while the Controlled Drugs and Substances Act allows nurse practitioners, potentially, to prescribe controlled drugs, at this point in time the Province of Ontario has not allowed that. A nurse practitioner working for Health Canada cannot prescribe controlled drugs in Ontario. But it's allowed in B.C., so they can prescribe in B.C.