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Vancomycin Concentration, Serum/Plasma (24-Hour Peak and Trough)

Published: August 9, 2026Updated: August 17, 2026

This test measures the amount of vancomycin, a medication used to treat serious bacterial infections, in your blood. It helps doctors determine the right dose to prevent toxic levels.

Quick summary

["Vancomycin levels guide safe dosing to fight infections without causing harm."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
85045-3
Short code
SA glyc resist vanc + teic IC Islt Grad
Synonyms
SA glyc resist vanc + teic IC Islt Grad
Category
glucose
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Critical range
0.5 N/A – —
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
gradient-strip-ard
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 vancomycin levels if you’re taking this antibiotic for conditions like staph infections, especially if you have kidney problems or are receiving long-term treatment. It helps ensure the drug stays effective while avoiding side effects like kidney damage or hearing loss.

How Is the Test Performed?

A blood sample is taken from a vein, usually in your arm. The sample is sent to a lab where vancomycin levels are measured using a sensitive test that detects the medication’s presence in your serum or plasma.

What Do the Results Mean?

Results are typically reported as a concentration range (e.g., peak and trough values) rather than a single reference range, as vancomycin dosing is individualized. Your doctor will interpret these values in relation to your treatment plan.

Possible Side Effects and Risks

While vancomycin is effective, high levels can cause side effects like kidney damage, red rash (red man syndrome), or hearing issues. Your doctor will monitor your levels closely to avoid these risks.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Ensuring Safe and Effective Treatment

Short name

Vancomycin Levels

Frequently asked questions

Why might my doctor ask for vancomycin levels before or during treatment?
Your doctor may need vancomycin levels to confirm the drug is working properly and to prevent toxic buildup. For example, peak levels check if the drug is high enough to kill bacteria, while trough levels ensure it doesn’t linger too long in your system.
How often will I need this test?
The frequency depends on your treatment plan. Some patients need levels checked daily or weekly, especially if they have kidney issues or are receiving high doses. Your doctor will let you know.
What if my results are outside the expected range?
If your levels are too high, your doctor may adjust your dose to lower the risk of side effects. If too low, they may increase your medication or switch to another antibiotic if needed.
  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 17, 2026. · Read our editorial policy