There are two stores that have great medication for Canadians. One is http://mops.ca/ , which is equivalent to the US store Petsolutions.com and such. Although I haven't seen Maracyn/Maracyn II at Mops, but they have other great meds like Triple Sulfa to substitute for the Maracyns. They also carry the antibacteria food from Jungle.
The other, more important, one is http://www.fishsempai.com, and Andrew sells Goldfishconnetion's Metromed and Medigold. He works with Rick to supply Canadians with the medicated foods, and some other stuff that Rick has, like Progold. Andrew is great to work with, and does overnight shipping.