Can someone please assist me with this answer (correctly: lol) I have looked online and only find various answers. If I am being prescribed Oxycodone, for my slipped disks in my back, and ran out 3 days before I go to my Dr's appointment, and use a fentynal patch, will there be a difference in the drug test? I am also on a low dose of methadone, as we are switching from the Oxycodone to Methadone. Basically, I don't want to ruin my pain managment program as I am doing very well with it, and my doctor is phenomenal, but I was wondering if there is a difference between the urine test, or because they are both opiate based, it will read the same. Thanks! By the way, it is a Calloway labs test cup, but reads a quick version on the cup for the dr.