Tobramycin, Serum, Trough
Also known as: AK-Tob™, Nebcin®, TOBI®, Tobrex®
Use
Tobramycin is administered to treat serious infections caused by aerobic gram-negative bacilli (eg, a number of the Enterobacteriaceae, P aeruginosa). These include lower respiratory tract, intra-abdominal, soft tissue, bone or joint, wound, and complicated urinary tract infections; bacteremias; and meningitis.
Special Instructions
Not provided.
Limitations
Tobramycin is cleared by the kidney and accumulates in renal tubular cells. Nephrotoxicity is related to the duration of trough levels exceeding 2 mcg/mL. Monitoring creatinine levels every two to three days is critical to predict renal toxicity. The initial toxicity presents as nonoliguric renal failure, typically reversible if the drug is discontinued. Ongoing administration may lead to oliguric renal failure. Nephrotoxicity occurs in 10% to 25% of patients receiving aminoglycosides but can be mitigated by monitoring and adjusting dosing schedules. Aminoglycoside ototoxicity, which causes hearing loss, is uncommon, and no clear correlation with plasma levels exists when levels are monitored and dosing is adjusted. Emerging dosing regimens complicate toxicity assessment.
Methodology
Immunoassay
Biomarkers
LOINC Codes
- 4059-2 - Tobramycin Trough SerPl-mCnc
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.3 mL
Container
Red-top tube or green-top (heparin) tube. Do not use a gel-barrier tube.
Collection Instructions
Transfer separated serum or plasma to a plastic transport tube. The trough sample is drawn immediately prior to the next dose.
Storage Instructions
Room temperature
Causes for Rejection
Gel tube; severe hemolysis; lipemia; icteric specimen
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 14 days |
| Refrigerated | 14 days |
| Frozen | 14 days |
Other tests from different labs that may be relevant