I was wondering something about drug tests. It sounds strange, but we had to take that test as a part of the job interview?! Anyway, I saw several people who were positive, but they did not seem like drug abusers at all. Actually, they were shocked when they got the results. Anyway, I did not get the job but I would like to know something. What causes false positives on a drug test?
We could be talking about many things here, both medical and non-medical. As for this second group, it includes a mistake in laboratory procedure, wrong paperwork, switching samples etc. The most common medical reason for false positive drug test are cross reactants. It is a substance that has similar chemical structure to a drug, thus it can be shown as the drug in the result. Ibuprofen, anti-depressants and some antibiotics are the perfect examples of cross reactants. Mass Spectrometry test might show the real situation.
Does buprenorphine ever cause a false positive for heroin?