Tobramycin, Serum, Trough

Casandra

Casandra Test Code LC48814Version 1 (DRAFT)

Performing Lab

Lab LabcorpLab Test ID 007155CPT Code 80200

Tobramycin, Serum, Trough

Also known as: AK-Tob™, Nebcin®, TOBI®, Tobrex®

Clinical Use

Order Test

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

Peak levels should be ordered using Test No. 007154. Trough levels should be ordered using Test No. 007155. Please label tubes appropriately as 'peak' and 'trough.'

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.

Test Details