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Fluoroquinolone Antibiotic Concentration in Serum

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

This test measures the amount of fluoroquinolone antibiotics (a class of medications used to treat bacterial infections) in your blood serum. It helps your healthcare provider determine if the medication is working effectively and adjust your dose if needed.

Quick summary

["This test helps ensure your antibiotic is at the right level to fight infection safely."]

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

Key facts at a glance

LOINC
39317-3
Short code
FLUAV N7 NAb Ser Ql Nt
Synonyms
FLUAV N7 NAb Ser Ql Nt
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
neut
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 doctor may order this test if you’re taking fluoroquinolone antibiotics to treat or prevent infections like urinary tract infections, respiratory infections, or certain types of skin infections. It’s often used to check if the drug is reaching the right concentration in your blood to kill bacteria while minimizing side effects.

What Does the Test Measure?

The test quantifies the presence of fluoroquinolone antibiotics in your serum. Common examples include ciprofloxacin, levofloxacin, and moxifloxacin. The result helps assess whether your dose is therapeutic (effective) or if adjustments are needed.

How Is the Test Performed?

A blood sample is drawn from a vein in your arm. The serum (liquid part of blood after clotting) is then analyzed using a sensitive laboratory method to measure antibiotic levels.

What Do the Results Mean?

Results are typically reported as a concentration value (e.g., micrograms per milliliter). Your doctor will compare this to your specific medication and dosing instructions to determine if your levels are within the target range for effectiveness and safety.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Fluoroquinolone Level

Frequently asked questions

How often should I expect this test?
This test may be done during or after treatment, depending on your condition and medication. Your doctor will schedule it based on your treatment plan, such as after a few days of starting antibiotics or during follow-up visits.
What are the possible side effects of fluoroquinolone antibiotics?
Fluoroquinolones can cause side effects like nausea, dizziness, or tendon pain. This test helps ensure your dose is appropriate to avoid excessive exposure, which could increase risks.
Can I drink water before the blood draw?
Yes, you can drink water before the blood draw, but avoid caffeine or alcohol for at least 30 minutes before testing to ensure accurate results.
  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