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Linezolid Concentration in Serum or Plasma

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

This test measures the amount of the antibiotic linezolid in your blood. It helps doctors check how well your body is responding to this medication.

Quick summary

["This test helps ensure your antibiotic dose is effective and safe."]

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

Key facts at a glance

LOINC
88706-7
Short code
Linezolid Islt Slgr Mcbct AB 1.0
Synonyms
Linezolid Islt Slgr Mcbct AB 1.0
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
method-for-slow-growing-mycobacteria-antibiotic-concentration-at-ug-ml
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 Is This Test Done?

Your healthcare provider may order this test if you’re taking linezolid to treat or prevent certain infections, such as bacterial pneumonia, skin infections, or bloodstream infections. It helps monitor your drug levels to avoid side effects or insufficient treatment.

What Does This Test Measure?

The test detects the presence and concentration of linezolid in your blood, typically collected from a vein or arm. This helps assess whether your body is absorbing and processing the medication as expected.

How Is the Test Performed?

A small sample of blood is drawn from a vein in your arm. The sample is then sent to a lab for analysis using an immunoassay method to measure linezolid levels.

What Do Results Mean?

Results provide a quantitative measure of linezolid concentration in your blood, which doctors use to guide treatment adjustments. While reference ranges vary by lab, they help ensure therapeutic levels are maintained without excessive exposure.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: This test is critical for patients on linezolid to prevent complications like drug resistance or toxicity. Proper dosing ensures the infection is fully treated while minimizing side effects such as bone marrow suppression or skin rash.

Short name

Linezolid Level

Frequently asked questions

Why might I need this test?
You may need this test if you’re prescribed linezolid for an infection, especially if you have conditions that require careful monitoring of antibiotic levels, such as kidney or liver issues.
What could affect my results?
Several factors may influence results, including your overall health, other medications you’re taking, kidney or liver function, and timing of the blood draw relative to your last dose.
How soon will I get my results?
Results are typically available within 1 to 3 business days, depending on your lab’s processing time. Your healthcare provider will discuss them with you during your follow-up visit.
  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