Big issue in germany right now. Random D&A tests have been put into law a few months back after severe lobbying of Lufthansa CEO Carsten Spohr, who is currently fighting a very dirty figh with his own pilots. Lufthansa personnel was actually drafting that part of the legislation.
However, the new law is flawed on several levels. It requires a union CLA or a regulation done with a works council, which can under german law only be established with another CLA by a union and is required for every airline that has a presence in germany, ryanair therefore would need union recognition. If neither a CLA nor a works council thingy exists testing is illegal. Therefore there is unequal treatment of pilotd dpending on union recognition or not, unionized airlines are basically punished for that.
Testing is done by the airline, doesn't have to be done by medically trained personnel although an MD has to be close by. Which kind of tests are used and which quota of the pilots has to be tested is not regulated, however blood tests are impossible as they are a crime in itself (sticking a needle into someone is assault under german law) and can only be done on request of the testee or when ordered by a judge. Breathalyzer tests are not admissible in court except from one very specific stationary apparatus that costs several hundred thousand € and has to br recalibrated every two weeks or so. Both the normal breathalyzer tests and every non invasive drug test have a very high rate of false positives, using a non alcoholic mouth wash before work could theoretically lead to losing your job. And there are no quick non invasive tests for psychopharmaka or other meds.
Another issue that most probably will have to be settled in front of the constitutional court is the case of the innocence presumption which is the cornerstone of our law system. The new law however turns that around and considers everyone to be guilty until proven otherwise. Even policeman cannot order a D&A test until they have a provable suspicion that someone is under the influence. Random testing is therefore illegal, except for pilots nowadays. Even during ramp tests the inspectors can only order a test if they have a suspicion they can defend in court that a pilot is under the influence.
Interesting times ahead on his one.
That said, i would much rather have a working peer support programme which can be approached by anyone without fear of repercussions and which gives a safe way back into the job, something some companies over here have, sadly not the one im working for as it costs money.
And no, i don't want to work with someone under the influence, luckily i never had to have that talk yet and suggest a sick call. But it might happen at some point. However, i have flown and flown with pilots so fatigued that they probably would have been better at their job with enough rest and one or two pints right before work...