When patents expire and generics come on the market, I think you would find that in virtually all pharmacies in Canada, the generic would be available to the patient.
I will use an example in the area of cholesterol. A drug called Lipitor came off patent and instead of generic prescriptions for Lipitor increasing as you might expect as the prices came down, the promotion to the medical community was for a different drug, Crestor, and sales of Crestor went up. Patients were often prescribed Crestor, when in the past they might have been prescribed Lipitor. Crestor was still being sold at a very high brand price, and the generic Lipitor was available at a low price. The problem was that Lipitor was not being used properly. Some insurance plans will require that as well. It's called “therapeutic substitution”, to ensure that the best-priced product is available. When the actual product, such as Lipitor, goes generic, I think you will find that pharmacies have it. The problem may be that it's not being prescribed.