If you go to gtaa.com (the Toronto airport website), you can easily find information saying what is allowed on board. Medication is for sure allowed, but I think there are restrictions on what packaging it has to be in. In other words, I think it has to be in something that looks official.

I haven't flown international out of Canada from any airport but Toronto. It's professional enough. It's just the three hours to get from parking lot to the plane that is bugging me. Put that on top of having to deal with Toronto parking etc, and it all adds up to a long trip before you've even left the ground. In the same time, I could be driving across the border and well into the second American state for wherever I'm going.