Skip to content

Tobramycin Concentration in Serum/Plasma (Mass Concentration)

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

This test measures the amount of the antibiotic tobramycin in your blood, often done to monitor drug levels in patients receiving this medication.

Quick summary

["Tobramycin levels help ensure the drug is at an effective dose without causing harmful side effects."]

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

Key facts at a glance

LOINC
31095-3
Short code
Tobramycin Trough EID SerPl-mCnc
Synonyms
Tobramycin Trough EID SerPl-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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, a strong antibiotic used to treat serious bacterial infections. It helps track how well your body is processing the drug and ensures it stays within safe levels to prevent resistance or toxicity.

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 long-term tobramycin therapy, your provider may schedule regular tests to monitor your levels.

What the Results Mean

Results are typically compared to your baseline or previous test results rather than a fixed range. Your provider will interpret the results in the context of your treatment plan, infection, and overall health.

Potential Side Effects of Tobramycin

High levels of tobramycin can cause side effects like kidney damage, hearing loss, or nerve damage. Your provider will adjust your dose if levels are too high.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Tobramycin levels are critical for managing infections caused by bacteria resistant to other antibiotics. Proper monitoring helps prevent overuse, which can lead to antibiotic resistance, and ensures the drug is effective while minimizing harm.

Short name

Tobramycin Level

Frequently asked questions

Why might my doctor want to check my tobramycin levels regularly?
Regular checks help ensure your tobramycin stays within safe levels, balancing effectiveness against potential risks like kidney or nerve damage. It’s especially important if you have kidney problems or take other medications that interact with antibiotics.
What happens if my tobramycin level is too high?
If levels are too high, your provider may reduce your dose, switch to a different antibiotic, or monitor you more closely to prevent side effects like kidney damage or hearing issues.
Can I eat or drink before this test?
You can eat and drink normally unless your provider instructs otherwise. Blood tests like this 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