This really is a sticky situation for you, and I understand your concerns. They are legitimate and well founded. I know that even Wal-Mart does drug screenings because my sister applied there and had to do one. Out of all the applicants, she was the only one who tested "clean" and was offered the position. It makes me feel so bad for the ones who are on legitimate pain management, because they are discriminated against- even though discrimination is illegal. I mean, how many of those people who tested positive for narcotics in their system were given the opportunity to explain why they have them in their system? How many people have been passed up for a job when they are more than sufficiently qualified, would show up every day and do a great job for the company have been turned down because of this? I'm sure the numbers are quite high.
I don't know what to tell you, other than that I agree with the others that unless a drug screening comes up, I wouldn't mention it. And if it does come up and is a requirement, getting a note from your doctor would be a good idea.
Most people don't understand that those of us who are in pain management are able to be medicated and still function. We have been on some of these meds long term, and therefore it's no different than taking a Motrin as far as the effects some of these meds have on us.
I wish you the best of luck in finding a new job. Please keep us posted.
Happy Holidays!