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Serum/plasma morphine concentration (quantitative)

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

This test measures the amount of morphine present in your blood, often checked to assess drug metabolism, toxicity, or compliance with medication regimens.

Quick summary

["This test helps doctors evaluate how your body processes morphine and whether it’s safe at your current dose."]

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

Key facts at a glance

LOINC
46259-8
Short code
Morphine Free SerPl Ql Scn
Synonyms
Morphine Free SerPl 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’re taking morphine or related pain medications. It can help determine how well your body is breaking down the drug, detect overdose risks, or monitor treatment effectiveness in certain conditions (e.g., chronic pain management).

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample, usually drawn from a vein in your arm. If you’re on a strict diet or taking certain medications, let your doctor know beforehand.

What the Results Mean

Results show the morphine concentration in your blood. Higher levels may indicate overdose, poor metabolism, or recent use of morphine. Lower levels could suggest rapid drug clearance or non-compliance. Your doctor will interpret results in the context of your medical history and symptoms.

Possible Causes of Abnormal Results

Elevated morphine levels might be due to recent morphine use, liver/kidney issues (which slow metabolism), or drug interactions. Low levels could result from rapid metabolism, missed doses, or certain medications that speed drug breakdown.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Morphine Level

Frequently asked questions

How often should I get this test?
The frequency depends on your treatment plan. For chronic pain management, tests may be done periodically (e.g., every few weeks) to adjust doses safely. If you’re in a hospital or monitoring for overdose, tests could be more frequent.
Can I drink alcohol before this test?
Yes, but avoid heavy alcohol use 24 hours before testing, as it may affect morphine metabolism and test accuracy.
Does this test show if I’m addicted to morphine?
No, this test measures current morphine levels only. Addiction assessment requires a full evaluation by a healthcare provider, including medical history, symptoms, and behavioral factors.
  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