Question about drug testing

I have in the past taken drug tests for a job. When I took these tests i was taking dexedrine by prescription from a doctor. This shows up as amphetimine on a drug test. When the doctor got the results he called me and told me I had tested positive for amphetimine and asked if I was taking any prescription medications to explain that. I told him I was prescribed dexedrine and he had me bring him the prescription. A couple days later I got a call from the workplace and I was hired. I assume he reported to the workplace that my drug test had come up clean, why else would he call me before reporting the results. I mean would it not be a violation of doctor patient confidentiality for him to report what prescription medication I was taking.

I now have a medical marijuana card and am currently looking for a job and will most likely soon take a drug test. My question is if I were to inform the tester of my medical marijuana card would they report to the employer that I tested positive for marijuana and amphetimine but that I was taking both legally or would they just report that my test had not revealed anything illegal. Again it seems like a gross violation of my doctor patient confidentiality for them to report to a workplace what prescription medications I am taking.

where r u from? canada? I have a green card here. and had to take a piss test. thought i might be able to get around it, not exactly... the government doesnt recognize it as a perscription drug, so basically you aren't legally protected from drug screening. company's can screen whoever whenever. unless you have one hell of a lawyer and sit down with h.r. people from the company thats doing the screening and try work something out, and if they're understanding they might let you keep ur job. but health canada wants nothing to do with it.