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HelpTest Code LAB4223 VANCOMYCIN, TROUGH
Specimen Type
Preferred Sample: Lithium Heparin Plasma (Mint Green Top, Dark Green Top)
Alternative Sample: Serum (SST, Gold, Corvac, Tiger, Red Top Tube)
* See Test Limitations on this page for information about tubes containing gel.
Specimen Volume
1 mL
Minimum Volume
0.5 mL
Turnaround Time
STAT: 1 hour
Routine: 4 hours
Test Schedule
Daily
Sample Stability
Refrigerated: 7 days
Frozen: 14 days
Method
Colorimetric
Reference Ranges
Vancomycin, ug/mL
Trough: 5.0-10.0 mg/dL
Toxic: >21.0 mg/dL
Reporting Limit
1.4-400.0 ug/mL
CPT Codes
80202
Test Components
Vancomycin, Trough, ug/mL
Collection Instructions
Draw trough within 15 minutes prior to infusion.
Limitations
Studies have shown that therapeutic drug levels may be altered in serum/plasma that remains in contact wiht separator gel. Therapeutic drug levels collected in an SST or PST should be run within 24 hours of collection.
Clinical Information
Vancomycin hydrochloride is a tricyclic glycopeptide derived from Amycolatopsis orientalis. It is commonly used in the treatment of methicillin-resistant Staphylococcus aureus infections. This glycopeptide inhibits the growth of the bacterium by intervening in the cell wall synthesis, thereby killing the bacterium. The peak therapeutic range for vancomycin is between 20 to 40 µg/mL and the trough is 5 to 10 µg/mL. Side effects of vancomycin are deafness (ototoxicity) and renal failure (nephrotoxicity) at levels above therapeutic range.
Vancomycin is absorbed minimally from the gastrointestinal tract and is usually given intravenously. In the first 24 hours, about 90% of the vancomycin is excreted unchanged by the kidneys. The average half-life in patients with normal renal function is about 6 hours. Vancomycin is approximately 55% bound to plasma proteins. Therapeutic serum levels vary depending on the microorganism involved and the patient’s tolerance to the drug. Vancomycin serum or plasma concentrations are monitored to guide therapy as individual patient differences require dose changes that are difficult to predict. Monitoring these levels decreases the frequency of serious toxic effects.