Free morphine concentration in urine (24-hour collection)
This test measures the amount of morphine (a pain medication) that is not bound to proteins in your urine over a 24-hour period.
["Assesses how much free morphine is excreted in your urine, which can help monitor drug levels and metabolism."]
Key facts at a glance
- LOINC
- 97280-2
- Short code
- Morphine Free TissCo Ql Scn
- Synonyms
- Morphine Free TissCo Ql Scn
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- screen
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Your healthcare provider may order this test if you are taking morphine or another opioid pain medication. Free morphine levels can help determine how your body is processing the drug, whether you are at risk for overdose, or if you need dosage adjustments. It may also be used in cases of suspected drug abuse or to monitor treatment in patients with chronic pain.
What to Expect Before the Test
You will need to collect all urine produced in a 24-hour period in a special container. Typically, you start the collection after waking up in the morning and continue until you wake up the next morning. Drink plenty of fluids to help ensure adequate urine production. Follow any specific instructions your healthcare provider gives you to avoid foods, medications, or substances that might interfere with the test.
During the Test
No special preparation is required beyond collecting your urine sample. The test involves sending the 24-hour urine sample to a lab for analysis. The lab will measure the concentration of free morphine in the urine.
After the Test
Once the lab completes the analysis, your healthcare provider will review the results and discuss them with you. This may include discussing your medication regimen, pain management strategies, or next steps based on the findings.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Free morphine levels in urine can indicate how effectively your body is metabolizing the drug. Elevated levels may suggest improper dosing, drug interactions, or potential risks of toxicity. In cases of suspected opioid abuse, these results can help assess exposure and guide treatment decisions. Monitoring free morphine can also be important in patients with kidney issues, as these organs play a role in drug metabolism and excretion.
Frequently asked questions
What does a free morphine urine test measure?
How is the urine sample collected for this test?
Can I take pain medications other than morphine before this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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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