Fluoroquinolone Antibiotic Level (Serum)
This test measures the amount of a fluoroquinolone antibiotic, such as ciprofloxacin or levofloxacin, in your blood. It helps your healthcare provider determine if the drug is working at the right level and adjust your treatment as needed.
["Your antibiotic dose may need to be changed based on this test result."]
Key facts at a glance
- LOINC
- 39313-2
- Short code
- FLUAV N3 NAb Ser Ql Nt
- Synonyms
- FLUAV N3 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 This Test Is Done
Your doctor may order this test if you’re taking a fluoroquinolone antibiotic for an infection, such as a urinary tract infection, bacterial pneumonia, or other serious infections. It helps ensure the drug is effective and avoids potential side effects by checking your blood levels.
What to Expect Before the Test
No special preparation is needed. You may have a small needle inserted into your arm to draw blood, similar to a routine blood test. The process usually takes a few minutes.
What the Test Results Mean
Results show the concentration of the antibiotic in your blood. Low levels may mean the drug isn’t strong enough to fight the infection, while very high levels could indicate side effects. Your doctor will interpret the results in the context of your treatment plan.
Possible Side Effects
Fluoroquinolones can cause side effects like nausea, stomach pain, or rare but serious issues such as tendon damage or nerve problems. If you experience severe pain, swelling, or weakness, contact your doctor immediately.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Antibiotic levels are critical for infections that require precise dosing, especially in patients with kidney issues or those taking other medications that interact with fluoroquinolones. Proper monitoring helps prevent resistance, toxicity, or ineffective treatment.
Short name
Fluoroquinolone Level
Frequently asked questions
Why might my doctor order this test?
What does a low or high antibiotic level mean?
Can I eat or drink before this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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