Warfarin Quantitative, Serum or Plasma
Also known as: WARF SP
Use
The Warfarin Quantitative test measures the level of warfarin in serum or plasma to help manage and adjust warfarin dosage and ensure therapeutic drug monitoring. Warfarin is an anticoagulant used to prevent and treat blood clots. Monitoring its levels is crucial to avoid under or over-anticoagulation, which can lead to serious side effects such as bleeding or thrombosis.
Special Instructions
The test is performed by a non-ARUP laboratory, and separate specimens must be submitted when multiple tests are ordered. Samples should be collected in Plain Red, Lavender (K2EDTA or K3EDTA), or Pink (K2EDTA) tubes, and must be separated from cells ASAP or within 2 hours of collection.
Limitations
The test is not chiral specific and does not distinguish between the R and S enantiomers of warfarin. Therefore, it provides a combined concentration. Additionally, this test is not cleared or approved by the US Food and Drug Administration. The results should be used in conjunction with the International Normalized Ratio (INR) for proper dosage adjustments, given the test's lack of chiral specificity.
New York Approved
Methodology
Mass Spectrometry
Biomarkers
LOINC Codes
- 4098-0
Result Turnaround Time
8-11 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.2 mL
Container
ARUP Standard Transport Tube
Collection Instructions
Separate from cells ASAP or within 2 hours of collection. Collect in Plain Red, Lavender (K2EDTA or K3EDTA), or Pink (K2EDTA) tubes.
Storage Instructions
Refrigerated. Also acceptable: Room temperature or frozen.
Causes for Rejection
Separator tubes.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 1 month |
| Refrigerated | 1 month |
| Frozen | 15 months |