How can Hydromorphone show up in your urine drug test if you are only taking Morphine ER and Oxycodone IR?

I think a short and sweet answer to this is that the body converts some hydrocodone into hydromorphone. Same thing with Oxycodone is converted to Oxymorphone.Hydrocodone Metabolizes to HydromorphoneHydrocodone may not cause a positive result in a standard opiate urine test. Many opiate tests test only for morphine (which both codeine and heroin break down into). This is true for both home/business kits and laboratory testing. Hydrocodone does not break down into morphine, and is therefore not detected by these tests.

But home and laboratory testing is available that will detect hydrocodone (and hydromorphone, which a small part of hydrocodone breaks down into when metabolized by the body.) So test results will depend on the particular type of test that is used and whether or not laboratory verification is required. If a home drug test is given and the opiate test shows a positive result (due to hydromorphone use), a laboratory verification might NOT result in a positive test because the lab may only test for morphine. In this case, the lab would NOT be able to verify the original positive result.