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HelpTest Code VANRA Vancomycin, Random, Serum
Useful For
Monitoring adequacy of drug concentration during vancomycin therapy whenever a specimen is submitted or collected without collection timing information
Method Name
Immunoassay
Reporting Name
Vancomycin, Random, SSpecimen Type
Serum RedOrdering Guidance
In addition to this random assay, both peak level and trough level testing are available.
1. Serum for a peak level should be drawn 1 hour after completion of dose; order VANPA / Vancomycin, Peak, Serum.
2. Serum for a trough level should be drawn no more than 30 minutes prior to next dose; order VANTA / Vancomycin, Trough, Serum.
Specimen Required
Collection Container/Tube: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions: Centrifuge and aliquot serum within 2 hours of collection.
Specimen Minimum Volume
0.25 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum Red | Refrigerated (preferred) | 14 days | |
| Frozen | 365 days | ||
| Ambient | 48 hours |
Reject Due To
| Gross hemolysis | Reject |
Clinical Information
Vancomycin is an antibiotic used to treat infections caused by gram-positive organisms that are resistant to beta-lactam antibiotics, such as methicillin-resistant staphylococci (MRSA), Streptococcus viridans group, penicillin/cephalosporin-resistant Streptococcus pneumoniae, and penicillin/ampicillin-resistant Enterococcus species. The oral formulation, which is not absorbed, is used in the treatment of pseudomembranous colitis caused by Clostridium difficile. Vancomycin is also used when patients are intolerant or allergic to beta-lactam antibiotics.
Vancomycin has been associated with nephrotoxicity and ototoxicity, although it appears that many of these reports reflected impurities in early formulations. Monitoring of vancomycin-related nephrotoxicity is recommended only for patients with reduced renal function, those receiving aggressive or prolonged vancomycin regimens, or those at high risk including patients comedicated with other nephrotoxic agents.
Trough concentrations are recommended for therapeutic monitoring of vancomycin, preferably acquired at steady state (just before fourth dose). To avoid development of resistance, vancomycin trough levels should remain above 10.0 mcg/mL. Complicated infections require higher target levels, typically 15.0 to 20.0 mcg/mL. Peak concentrations do not correlate well to efficacy or nephrotoxicity, but may be useful for pharmacokinetic studies or for select patients.
Random levels may be ordered when attempting to determine when to dose vancomycin in patients with renal impairment or those undergoing dialysis.
Reference Values
VANCOMYCIN, TROUGH
Therapeutic: 10.0-20.0 mcg/mL
VANCOMYCIN, PEAK
Therapeutic: 20.0-45.0 mcg/mL
Interpretation
Trough levels correlate better with efficacy than peak levels, with target trough levels of 10.0 and 20.0 mcg/mL, depending on the type of infection.
Peak levels are not recommended for monitoring, except in select circumstances such as when performing pharmacokinetic analyses (eg, area under the curve: AUC determinations). Typical peak levels are between 20.0 and 45.0 mcg/mL.
These levels are consistent with Mayo Clinic Antimicrobial Therapy Guidelines.
Cautions
As with any assay employing mouse antibodies, the possibility exists for interference by human antimouse antibodies (HAMA) in the sample, which could cause falsely lowered results.
Unspecific binding of heterophilic antibodies from the sample to glucose-6-phosphate dehydrogenase of the reagent may lead to falsely lower test results in very rare cases (<10[-6]).
Method Description
The assay is based on the kinetic interaction of microparticles in solution (KIMS). Vancomycin antibody is covalently coupled to microparticles and the derivative is linked to a macromolecule. The kinetic interaction of microparticles in solutions is induced by binding of drug-conjugate to the antibody on the microparticles and is inhibited by the presence of vancomycin in the sample. A competitive reaction takes place between the drug conjugate and vancomycin in the sample. A competitive reaction takes place between the drug conjugate and vancomycin in the serum sample for binding to the vancomycin antibody on the microparticles. The resulting kinetic interaction of microparticles is indirectly proportional to the amount of drug present in the sample.(Package insert: Roche Vancomycin reagent, Roche Diagnostic Corp, Indianapolis, IN. 2016-09 Ver. 1)
Day(s) Performed
Monday through Sunday
Report Available
Same day/1 to 2 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
80202
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| VANRA | Vancomycin, Random, S | 20578-1 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| VANRA | Vancomycin, Random, S | 20578-1 |