Tobramycin, Trough, Serum
Use
This test is useful for monitoring the adequate clearance of tobramycin near the end of a dosing cycle. Tobramycin is an antibiotic used to treat serious infections caused by gram-negative bacilli, including Citrobacter freundii, Enterobacter species, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Providencia stuartii, Pseudomonas aeruginosa, and Serratia species. Therapeutic drug monitoring can help avoid toxicities such as ototoxicity and nephrotoxicity, especially when used alongside other ototoxic or nephrotoxic drugs.
Special Instructions
If not ordering electronically, complete, print, and send a Therapeutics Test Request form with the specimen. Draw blood no more than 30 minutes before the next scheduled dose. Ensure serum gel tubes are centrifuged within 2 hours of collection. Red-top tubes should also be centrifuged, and the serum aliquoted into a plastic vial within the same timeframe.
Limitations
While this test provides essential monitoring for tobramycin clearance, it does not account for individual patient variability in drug metabolism or interactions with other medications that might alter drug levels. Toxicities such as ototoxicity and nephrotoxicity require additional monitoring through serum levels and renal function. Long-term use may necessitate audiology and vestibular testing.
FDA ApprovedNew York Approved
Methodology
Immunoassay
Biomarkers
LOINC Codes
- 4059-2
- 4059-2
Result Turnaround Time
1-2 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
0.5 mL
Minimum Volume
0.25 mL
Container
Plastic vial
Collection Instructions
Draw blood no more than 30 minutes before the next scheduled dose. Centrifuge serum gel tubes within 2 hours of collection. Red-top tubes should be centrifuged, and the serum aliquoted into a plastic vial within 2 hours of collection.
Storage Instructions
Refrigerated (preferred) for 7 days, ambient for 72 hours, frozen for 28 days.
Causes for Rejection
Gross hemolysis
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 hours |
| Refrigerated | 7 days |
| Frozen | 28 days |