My Doctor Ran A U.A On Me And The Test

My doctor ran a U.A on me and the test came back that I had taken Demerol. The last time I had it Was in 2010. also at the time of the test, my urine was brown indicating the possibility of another kidney stone. I take Cymbalta for pain klonipin, 2400 mg of Ibuprofen a day and my doctor also had me on Norco 10's twice a day. Can these drugs cause such a false reading? The last time I had demeril was in 2010 from an mva. I do not take it because it does not eliminate pain. I am 63 years old and prefer not to take the drug;it doesn't work on me. can you help me? My doctor now does not trust me because of the false positive.