Noroxymorphone/Creatinine Ratio, Urine — Confirmatory Test
A urine test measures noroxymorphone, an opioid metabolite, relative to creatinine. It can help assess exposure to oxycodone or oxymorphone.
["This test can help determine whether urine contains noroxymorphone, a metabolite associated with certain opioid medications."]
Key facts at a glance
- LOINC
- 86609-5
- Short code
- Noroxymorphone/Creat Ur Cfm
- Synonyms
- Noroxymorphone/Creat Ur Cfm
- Category
- kidney
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- confirm
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
What is this test?
This test measures the amount of noroxymorphone in urine compared with the amount of creatinine. Noroxymorphone is a metabolite that can be produced after taking oxycodone or oxymorphone.
Why might I need this test?
This test may be ordered to help monitor use of prescribed opioid pain medicines, support a urine drug-testing program, or evaluate suspected drug exposure. It is often used to confirm a result that was first detected by a urine drug screen.
How is the test performed?
A urine sample is collected and tested in the laboratory for noroxymorphone and creatinine. The results are compared with each other, which helps account for differences in how concentrated the urine is.
How do I prepare for the test?
Collect the urine sample in the container provided and follow the collection time or other instructions given by the laboratory or your clinician. Fasting is generally not required, but tell your clinician about all medicines and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Detecting noroxymorphone may indicate recent exposure to oxycodone, oxymorphone, or a medicine that is converted to one of these compounds. The result must be interpreted using the collection time, expected medication, dose, urine concentration, and laboratory method. A negative result does not completely exclude earlier exposure, and a positive result should be reviewed with the healthcare professional ordering the test.
Short name
Urine noroxymorphone/creatinine ratio
Frequently asked questions
What does a detectable noroxymorphone result mean?
Why is creatinine included in this urine test?
Does a negative result rule out opioid use?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy