Why are prescription drugs cheaper in Canada?

I think the question say it all. We all know they’re cheaper, but why? Is there some law in place keeping prices low? Are they subsidized? Is it that the Canadian govt runs the medical system and won’t pay more? There has to be some solid reason for this, because I’m not sure market forces can account for it - I mean are United States citizens really willing to pay twice as much or more for prescription drugs than citizens of other companies?

I can’t believe that this hasn’t been discussed here, unless everyone knows the answer. If it has, no need to summarize, just point me at the thread.(I did search, but no dice on this specific question)

make that first ‘say’ ‘says’ , and change the ‘companies’ to ‘countries’ and it might read a little more coherently…

See http://money.cnn.com/2003/03/13/news/drugs_canada/

Seems that “in Canada …government price-caps keep a lid on costs.”