If the government of Canada makes it illegal to use any drug substance, then doctors would not be able to practice medicine because even prescription and over-the-counter medications are considered drugs. While narcotics should be closely monitored, it would not be beneficial to make all drugs illegal and would, in fact, have a negative impact on society.
Definitely Not, to put it bluntly, people need their drugs, some people would do anything to get their drugs. Illegalization would just be a inconvenience.
Take for example Prohibition in America, when Congress only made alcohol illegal it created a whole era of illegal conduct, arguably its what made the whole Mafia. The last thing we need is a new type of criminal organization.