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Fluoroquinolone Antibiotic Concentration (Serum)

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

This test measures the amount of a fluoroquinolone antibiotic in your blood. It helps doctors determine if the drug is working properly and whether you need to adjust your dose.

Quick summary

["Your fluoroquinolone levels help ensure safe and effective treatment."]

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

Key facts at a glance

LOINC
41136-3
Short code
FLUAV N7 Ab Ser Ql
Synonyms
FLUAV N7 Ab Ser Ql
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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

Doctors may order this test if you’re taking fluoroquinolone antibiotics (like ciprofloxacin or levofloxacin) to monitor your blood levels. Proper dosing depends on how your body processes the drug, and this test helps prevent side effects or ineffective treatment.

What to Expect Before the Test

No special preparation is needed. You’ll likely have a small needle inserted into your arm to draw a blood sample. The process is quick and usually painless.

What the Results Mean

Results help your healthcare provider check if your antibiotic levels are within the target range for your condition. If levels are too low, your treatment may need adjustment. If levels are too high, it could signal side effects.

Common Uses and Conditions

This test is often used in patients with infections (like urinary tract infections, respiratory infections, or skin infections) where fluoroquinolones are prescribed. It’s also used in some cases of chronic conditions requiring long-term antibiotic therapy.

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 get this test?
Your doctor will determine the frequency based on your treatment plan, how long you’ve been taking the drug, and your kidney function. Typically, it’s done during or shortly after starting treatment, then periodically if needed.
What do my results indicate if they’re outside the normal range?
If results are too low, your antibiotic may not be working effectively, and your doctor might increase your dose or switch medications. If results are too high, it could mean you’re experiencing side effects like nausea, dizziness, or tendon pain, and your dose may need adjustment.
Can I eat or drink before this test?
Yes, you can eat and drink normally before the test unless your doctor instructs otherwise. This test only requires a blood sample, so fasting isn’t necessary.
  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