In my time on army.ca I don't recall coming across this subject, or at least not asked as directly as this.
In the Regular force, you are no longer on a provincial health plan. When I joined, my Ontario Health card was taken away. The only health card I have now is the Blue Cross card that the CF issued me. For drugs and the like, you will get all that you require upon reporting to the MIR, they decide what you need and they give it to you on the spot. Anything else that you may require will also be provided for you, ie dental checkups, cleanings, surgery, etc.
The Reserves are a little different, they're still covered under their provincial health care. I'm not sure how it works for Class B or C or for deployments. I can't offer a lot of details on how the Reserve system works since it's been quite a while since I was there.