Fired from job on first week because employer thought I was taking drugs and drinking at work

OP if you were working in an environment where taking even prescription medication could potentially hinder your ability to do you job in a safe manner, you should have probably disclosed that to them at either the interview stage, offer stage or once you started to your manager. They then would have been aware and able to deal with it in a better manner.

In regards people saying about defamation claims - if they other workers brought concerns to the manager, these would be protected under whistleblowing legislation from retaliation. You would have to prove the claims were brought maliciously in order to get the person fired, which is very difficult to do, rather than concerned co-workers. And they don't have to have been concerned about the OP, they can legitimally be concerned about themselves depending on the operating environment of the workplace. If you worked in a warehouse & saw someone who seemed to you to be dizzy or out of it working with you, you'd say something to the boss.

OP. This sums up your situation perfectly.

Your employer shouldn’t have done what they did and if you really wanted, you could make a complaint of discrimination to the WRC.

But unless you’re particularly dependent on that job or unless you feel genuinely hurt, the above advice is probably more prudent. Square it with the former employer and move on.

What was your role and duties and the type of work environment.

When questioned you should have mentioned the prescription medication.

The problem is you don't have any rights because you're there too short.

It's also possible that you were engaged in heavy duty and other kind of senstive work and you were taking prescription drugs on doctor's orders and that wasn't a good choice for the kind of work you were supposed to do?

But in the end, they should have given you a fair test or asked you or offered any proof if you were drinking at work?

Just hearing from staff is just hearsay about potential drinking on the job and then getting fired over hearsay is neither professional nor fair, but what fair is these days…. Work and job life isn't very nice these days.