Most places i know have a "3 strike "policy.
When being tested ,asked if and what medication your on.
If positive, sent home on pay until properly tested ,and if illegal drugs present,stay off work until you pass the test again.
Same with alcohol ,P-Off until it drops below required limit..
The hardest one to pass is the good old "joint".If you enjoy them frequently,then its in your system for up to 2 weeks.
The good hard stuff doesnt last long at all.
I dont agree with the "whacky Weed' one as i cant believe your still up with the pixies the next day.
I know quite a few people on their last chance and had to give it away.
So theres no big deal in it unless you participate,which quite a few do--------there lies the problem.
I should say (hope) pilots are clean ,but in these days of "duty of care" regulations ,could you imagine the concequences to Qantas if it was proven they allowed someone to work effected by booze or drugs and they caused some king of accident or harmed passengers in any way.
Just that word "random" goes a long way in a court-------it shows they do it.
And if ya real lucky some bird might even hold it for you when you pee in the bottle.