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Tobramycin Concentration in Serum or Plasma (Mass Concentration)

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

This test measures the amount of the antibiotic tobramycin in your blood. Tobramycin is used to treat serious bacterial infections.

Quick summary

["Tobramycin levels help doctors monitor how well your body is responding to treatment and check for potential side effects."]

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

Key facts at a glance

LOINC
73115-8
Short code
Tobramycin ind plt IgG SerPl Ql FC
Synonyms
Tobramycin ind plt IgG SerPl Ql FC
Category
hematology
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
flow-cytometry
CPT
82784
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 healthcare provider may order this test if you’re taking tobramycin to treat infections, such as pneumonia, urinary tract infections, or bloodstream infections. It helps ensure the drug is at an effective dose and avoids harmful levels.

What to Expect Before the Test

No special preparation is needed. A blood sample is taken from a vein in your arm, usually by a healthcare professional. You may feel a small pinch, but it’s quick and shouldn’t cause discomfort.

What the Results Mean

Results help your doctor adjust your tobramycin dose if needed. Too much can cause kidney damage or nerve issues, while too little may mean the infection isn’t fully treated. Your doctor will discuss these findings with you.

Possible Side Effects or Risks

Tobramycin can cause side effects like kidney problems, hearing loss, or allergic reactions. Rarely, it may affect your nerves. Always report any unusual symptoms to your doctor.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Monitoring tobramycin levels is critical for patients with kidney disease or those receiving high doses. It prevents toxicity while ensuring the antibiotic remains effective against bacteria. Results guide dosing adjustments to balance safety and treatment success.

Short name

Tobramycin Level

Frequently asked questions

How often should I get this test?
Your doctor will determine the timing based on your treatment plan, typically every few days or weeks during therapy.
What does a ‘normal’ result mean?
There’s no single ‘normal’ range for tobramycin because it varies by patient, dose, and kidney function. Your results will be interpreted in relation to your specific treatment needs.
Can I eat or drink before this test?
You can eat and drink normally unless instructed otherwise, as blood tests don’t require fasting.
  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