Rogue Spades: To  Call or Not To Call?

There have been enough cases of medical professionals nder the influence of mind alteing substances while at work to warrant the current debate: shoud we randomly and periodicaly drug-test our doctors?
Dr. Leape thinks so and supports, "We have a responsibility to identify problem doctors and bring them into treatment."
In the article, "Should physicians undergo random drug testing?", Jeffery Parks MD, explains that he understands there are conditions under which we don't want our doctors to practise on us, but, does not support the motion to drug test the docs.
Dr. Parks chooses to stand on the side of the doctors saying, "This totalitarian encroachment on what a man or woman chooses to do in his or her free time is rather disturbing."  Parks goes on to say that those who are operating under the influence are rarely under the radar; at some point it becomes obvious that you have a problem.  It is the responsibility of those around you to confront the issue head-on.
While Parks does not differentiate between casual and chance participation or heavy addiction, (excessive alcohol consumption included), he does make a strong case for those socially responsible individuals who choose to partake in such activities on their own time.
The question here is whether or not the law has the duty of picking up the slack the medical professionals have left by not dealing with the problem internally, before it became so widespread as to be a matter of public concern.
Parks would make the argument that, yes, "we have a responsibility to identify problem doctors and bring them into treatment" but we also have the responsibility of protecting these Americans' right to privacy that they still have the unalienable right to enjoy.
Just because we're too timid or cowardly to call a spade a spade ourselves, doesn't mean we need to involve the law, it's reprecussions or peoples' reputations.  This can all be handled in a more constructive, sensitive, private way; we should explore alternative processes to ensure we will not implement procedures that are ultimately more detrimental to the field of medicine than the behaviors discussed here.