Yes... You aren't entitled to employment in Canada if you are proved to be an addict. You can't be terminated though if full time and prove have an addiction ... If you are temp though .. Which I'm taking from your Q , you have nothing to make an argument,
Can an employer in alberta canada resind an offer of employment if you are prescribed methadone and signed off fit for duty with no restrictions?
Just to let you know I studied some case law in alberta being in the methadone program you are considered a disability and it is against the alberta human rights code to not hire on this because it is classified discrimination under the ahr