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Naloxone and Creatinine, Urine

Published: August 9, 2026Updated: August 16, 2026

A urine test measuring naloxone, an opioid-reversal medicine, and creatinine, which helps show how concentrated the urine sample is.

Quick summary

["This test can document whether naloxone is present in the urine while accounting for differences in urine concentration."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
107257-8
Short code
Naloxone/Creat Ur
Synonyms
Naloxone/Creat Ur
Category
kidney
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 naloxone and creatinine in a urine sample. Naloxone is a medicine that reverses the effects of opioids, while urine creatinine helps indicate whether the sample is concentrated or diluted.

Why might I need this test?

A clinician may order this test to determine whether naloxone has been administered or is present in the urine. It may be relevant when evaluating opioid exposure, an opioid overdose, or treatment with naloxone.

How is the test performed?

A urine sample is collected and analyzed in a laboratory. The laboratory reports the amount of naloxone and the creatinine level so the naloxone result can be considered alongside urine concentration.

How do I prepare for the test?

Follow the collection instructions provided by the healthcare professional or laboratory. If directed, provide a clean-catch urine sample in the designated container at the specified time and tell the clinician about any naloxone or other opioid medicines you received.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Urine naloxone and creatinine

Frequently asked questions

Does a positive naloxone result mean someone had an opioid overdose?
No. It shows that naloxone is present, but it does not alone prove an overdose or identify the reason it was administered. The result must be interpreted with the medical history and other findings.
Why is creatinine measured with urine naloxone?
Urine creatinine helps indicate how concentrated or diluted the urine is. This context is important because the same urine amount can contain different analyte concentrations depending on hydration.
Can this test tell me how much naloxone I received?
It may show that naloxone was present in the urine, but factors such as dose, timing, metabolism, and urine concentration affect the result. It is not a direct measurement of the administered dose.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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