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Serum Gentamicin Concentration (High-Potency Form)

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

This test measures the amount of gentamicin, a strong antibiotic, in your blood. It helps doctors monitor how much of the drug is in your system to ensure safe dosing.

Quick summary

["Gentamicin levels are checked to prevent dangerous side effects from too much antibiotic."]

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

Key facts at a glance

LOINC
35817-6
Short code
Gentamicin Islt GS High potency
Synonyms
Gentamicin Islt GS High potency
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
gradient-strip-high-potency
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 order this test if you’re taking gentamicin, a broad-spectrum antibiotic used to treat serious bacterial infections. It helps ensure the drug stays at effective levels while minimizing harm to your kidneys and nerves.

What to Expect Before the Test

No special preparation is needed. A healthcare provider will draw blood from a vein in your arm. You may feel a slight pinch, but it usually takes only a few minutes.

What the Results Mean

Results help doctors balance the antibiotic’s effectiveness with its risks. Too little may mean the infection isn’t fully treated, while too much can cause kidney damage or hearing loss.

Common Side Effects of Gentamicin

Gentamicin can cause side effects like nausea, dizziness, or hearing changes. Your doctor will adjust your dose based on these results to keep you safe.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

High levels of gentamicin in the blood can indicate overdose or poor kidney function, which may require immediate medical attention. Low levels might mean the infection isn’t being fully treated.

Short name

Gentamicin Level (Serum)

Frequently asked questions

How often should I expect this test?
Your doctor will schedule follow-up tests based on your treatment plan, typically every few days during active therapy.
What happens if my results are abnormal?
If your results are too high, your doctor may reduce your dose or switch to a gentamicin-free antibiotic. If too low, they may increase your dose or check for infection spread.
Can I drink water before the test?
Yes, you can drink water as usual, but avoid caffeine or alcohol before the blood draw.
  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