Tobramycin Concentration in Serum or Plasma
This test measures the amount of the antibiotic tobramycin in your blood, typically to check how well it’s working or to monitor your levels if you’re taking it for an infection.
["Tobramycin levels help doctors ensure you’re getting the right dose to treat infections safely."]
Key facts at a glance
- LOINC
- 7055-7
- Short code
- Tobramycin Islt Grad strip
- Synonyms
- Tobramycin Islt Grad strip
- 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
- 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 being treated with tobramycin, often for serious infections like pneumonia, sepsis, or certain types of bacterial infections. It helps track how your body is responding to the medication and prevents potential side effects.
What to Expect Before the Test
No special preparation is needed. You’ll likely have a small needle inserted into your arm or vein to draw a blood sample. If you’re on tobramycin, your provider may ask you to stop taking it for a short time before testing to get an accurate reading.
How the Test Works
Blood is collected and sent to a lab, where it’s analyzed using a sensitive method to measure tobramycin levels. The lab checks for the antibiotic’s presence and concentration in your serum or plasma.
Possible Results and Interpretation
Results are compared to standard guidelines for tobramycin dosing. Low levels may indicate the medication isn’t working effectively, while very high levels could suggest toxicity or improper dosing. Your provider will discuss these findings with you.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Tobramycin is a potent antibiotic used for infections resistant to other drugs. Monitoring levels helps prevent overuse (leading to resistance) or underuse (leading to untreated infections). It’s especially important for patients with kidney issues, as the drug is filtered by the kidneys.
Short name
Tobramycin Level
Frequently asked questions
Why might I need this test?
What does a normal or abnormal result mean?
Do I need to prepare for this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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