Flying-Spike:
Granted you may have to wait a day or so to be cleared
The CASA doctor presenting the seminar I went to stated that this process of clearing your name in an innocent positive could take up to two weeks.
I agree with the thrust of your comment that we should be careful what we ingest in the name of medicine. As flight crew this is particularly important in our operation of machinery.
I can tell my Chief Pilot/Engineer/DAMP Officer that I am on XXX medication and that I have altered my duties accordingly. That's not an issue.
The biggest problem I have is that if I voluntarily remove myself from flying duties due to medication but help out in the office I can still be randomly tested by CASA and return positive. Then it's up to two weeks being stood down.
IMHO the scope of who is able to be randomly tested by CASA's outsourced testers, and when, needs to be urgently reviewed.