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Levofloxacin concentration in serum/plasma (quantitative)

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

This test measures the amount of the antibiotic levofloxacin in your blood. It helps doctors check if the drug is working properly and adjust your dose if needed.

Quick summary

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

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

Key facts at a glance

LOINC
76040-5
Short code
levoFLOXacin Islt Slgr Mcbct AB 1.0
Synonyms
levoFLOXacin 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 levofloxacin to treat or prevent infections. It helps monitor how much of the drug is in your blood to prevent side effects or ensure the infection is fully treated.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into your arm or vein to draw blood. If you’re on a long-term course, your provider may check levels at specific intervals.

What the Results Mean

Results are used to guide treatment decisions, such as adjusting your dose or switching medications. Your provider will discuss these with you based on your medical history and symptoms.

Common Uses for This Test

This test is often used in patients with infections like pneumonia, urinary tract infections, or skin/soft tissue infections where levofloxacin is prescribed. It may also be used in monitoring patients with kidney or liver issues.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Ensuring Safe and Effective Treatment

Short name

Levofloxacin Level

Frequently asked questions

Why might my doctor want to check my levofloxacin level?
To confirm the drug is reaching the right amount in your blood to fight the infection without causing harmful side effects. Low levels may mean the infection isn’t being treated well, while high levels could increase risks like kidney damage or allergic reactions.
How often will I need this test?
This depends on your treatment plan. Some patients may need it once during therapy, while others (e.g., long-term use or certain conditions) may need it more frequently, such as weekly or monthly.
Can I eat or drink before the test?
You can eat and drink normally unless your provider instructs otherwise. Avoid alcohol or certain medications that might affect the test 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