I take several medications including OxyContin 40 and 15mg oxcodone , soma 350, I have.5 Xanax and 5 mg Valium I. Took a urine test and my urine showed high content of methadone. How can that happen??? I Also take wellbutrin cymbolta furosemide, pantaprozole,atorvastin,klor con,levoxathrine . I was so upset I asked for a new urine test right away. As I was searching for an answer I read about false positives, any chance a mixture of any of these could cause that.... I have had several urine tests before and I never had a problem.. Thank you , lynne