I take oxymorphone Er and failed my urine drug test, why?

[Nichole_R]

I’ve been taking 5mg oxymorphone extended release pills for 8 years. I recently had to switch primary care doctors because mine moved away. The first urine drug test I was asked to do was last Friday and they called today and said the drug didn’t show up in my system, and dropped me as a patient. I should start withdrawals tomorrow & I’m scared out of my mind. I’ve never failed a drug test, asked for an early refill, nothing like that. Please help :,(

[backhurtz]

When was your last dose taken before the test? 5 mg is a tiny dose, and I believe the test needs to be specifically requested since it is a semisynthetic opiod, not a traditional opiate.
Although oxymorphone is much more potent than other opiates, if you drank a lot of water, urinated frequently prior to the test or it wasn't sent out for confirmatory testing, it is possible an in office screen could show false negative.
The withdrawal symptoms can be managed using over the counter remedies, imodium, gatorade, and hylands restless legs are typically suggesred.

[Nichole_R]

They processed the test at our local hospital. I had taken my last dose approximately 10 hours before the test was collected. I’ve seen a number of other posts about false negative tests for this drug & was hoping someone could tell me how to proceed.

[backhurtz]

https://www.practicalpainmanagement.com/treatments/pharmacological/opioids/oxycodone-oxymorphone-metabolism
The  cut off for a positive result vary, but if immunoassay/GCMS testing was not done, and the detection level was 100ng/ml , it may be the dose of Opana is too small to be detected.