Do newly hired professors have to take a drug test before they start? In U.S., Canadian and European universities do new professors have to pass a drug test before starting their career?  Or is it only required when they are promoted to full-time tenure professors?
Is this a serious question? I would refuse to work anywhere where my employer would require me to do such a test. It is simply none of their business.

I am actually not aware of any (European) university that would require anyone to take a drug test. In fact, it would be illegal in many countries to do this (or at least, there are very strict rules about the circumstances in which it would be legal).