Skip to content

Naproxen and Creatinine, Urine

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

A urine test that measures naproxen and creatinine to assess drug exposure while accounting for urine concentration.

Quick summary

["This test can confirm that naproxen is present in the urine and help interpret the drug level relative to urine concentration."]

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

Key facts at a glance

LOINC
87784-5
Short code
Naproxen/Creat Ur Cfm
Synonyms
Naproxen/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 naproxen, a nonsteroidal anti-inflammatory medicine, and creatinine in a urine sample. Creatinine may be used to help account for differences in urine concentration when interpreting the naproxen result.

Why might I need this test?

A clinician may order it to assess recent naproxen exposure, investigate medication use or overdose concerns, or monitor treatment. It may also be used in workplace or other drug-testing situations when naproxen is specifically included.

How is the test performed?

A urine sample is tested in the laboratory to detect and quantify naproxen and measure creatinine. The report may present the results individually or as a naproxen-to-creatinine ratio, depending on the test ordered.

How do I prepare for the test?

Collect the urine sample at the time specified by your clinician, using the provided container and following the laboratory's collection instructions. Tell the clinician when you last took naproxen, and do not stop prescribed medication without medical advice.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Urine naproxen

Frequently asked questions

Does this test show how much naproxen is in my blood?
No. It is performed on urine and does not directly provide a blood naproxen concentration. Results primarily reflect recent exposure and how concentrated the urine is.
Why is creatinine measured with urine naproxen?
Creatinine helps account for how dilute or concentrated the urine is. This can make the naproxen result more useful when urine samples have different water contents.
How soon after taking naproxen will it be detected?
Naproxen and its metabolites can generally be detected in urine after a dose, but the detection window varies with dose, kidney function, hydration, and other factors. Your clinician can interpret the result in relation to the time you took the medication.
  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