I am routinely given urine tests at the pain clinic I go to. I take oxycodone 7.5/325, and Lyrica for fibromyalgia and arthritis, my last urine test indicated positive for hydrocodone (a fairly high level) and negative for oxycodone. I have never had this problem before. I did take another test but don t know the results yet. Why would this occur? I had actually taken 2 of my 4 oxycodone for the day by the time of day I took the test. Very confused as to how a med. I don t take showed up and the one I do didn t. Thanks for your help.