Tobramycin (Nebcin®), Random Level

Tobramycin (Nebcin®), Peak Level

Epic Mnemonic
Sunquest Mnemonic

LAB36
TOBRP

Category

Chemistry

Methodology

Enzyme Immunoassay

Test Performance Schedule

Sunday - Saturday

Result Availability

Within 24 hours

Container

Preferred:Gold top (SST) tube, Red top (serum) tube, or Green top (lithium heparin) tube
Alt: Lavender top (EDTA) tube

Volume

Pref. Vol.: 1.0 mL serum
Min. Vol.: 0.5 mL serum

Collection Instructions

• IV Infusion: Collect 30 minutes after end of drug infusion

• IM Injection: Collect 60 minutes after time of injection

• Routine venipuncture

• Immediately after collection, gently invert tube 5-10 times

• Clot 30 minutes

• Promptly centrifuge 10 minutes

• If no gel barrier is present immediately transfer serum or plasma to a plastic tube and refrigerate

• Properly centrifuged gel barrier tube does not require transfer of serum or plasma to separate tube

Transportation Instructions

Refrigerated

Stability

• Refrigerated: 3 days

• Frozen: 1 month

Causes for Rejection

• Mistimed specimen collection

CPT Codes

80200

Effective/Revised

03/29/2017

Tobramycin is an aminoglycoside antibiotic used in the treatment of infections caused by Pseudomonas aeruginosa, Proteus species, E. coli, Klebsiella, Serratia, Citrobacter, Staphylococcus aureus, Enterobacter and other microorganisms.

Tobramycin’s toxic effect is produced by interfering with ribosomal protein synthesis. Tobramycin undergoes very little, if any, metabolization and is, therefore, eliminated as the parent drug by glomerular filtration. The half-life of tobramycin in serum or plasma correlates closely with renal function and thus is quite variable between individuals and within one individual over time.

Serum or plasma tobramycin concentration is also impacted by mode of administration, the volume of extracellular fluid, the duration of the treatment and physiological changes during the illness and therapy.

The therapeutic range of tobramycin should be measured at peak as well as trough concentrations.

In patients with pre-existing renal damage or those to whom tobramycin has been administered for prolonged periods or in doses above the therapeutic range, hearing impairment and/or nephrotoxicity may develop. Therefore, monitoring of peak and trough tobramycin serum or plasma levels is critical in the prevention of these serious complications with the adjustment of dosage administration as indicated.