While you can carry your Schedule F medication when returning from abroad you are not allowed to receive it in the mail (http://www.hc-sc.gc.ca/dhp-mps/compli-conform/import-export/gui-0084_biu-uif-eng.php). So what do expats do in Canada if they are taking medication not available in North America and don't want to change their treatment???? I am nonplussed and noone seems to be able or want to help.
There is not a lot of "active ingridients" in various medicines that are not allowed in US or Canada but are allowed elsewhere in the world. Chances are that the medicine you seek is available in Canada under a different brand name or as a generic.
If the issue is specific dosage then again you should look to see what is available because same medicine may be available in various dosages so for example 600mg of X is the same as 6x100mg of X though the number of tablets/injections will be more.
In addition to that any chronic condition need to be monitored by a doctor to make sure that it is unchanged and the drug is still effective (especially if the condition persists over decades).
So having said all that if you want a particular brand of particular medication with particular dosage that is not available in the country then your only option is to have someone or yourself bring this particular medication from the country where it is available.