Doxepin Level (including Nordoxepin)
Sinequan, Doxepin Level
Antrim #17252, EPIC: LAB5388, SOFT: DOXEP
Specimen Collection Criteria
Collect: One plain Red-top tube. (Minimum Whole Blood: 2.0 mL)
Do not use Serum Separator Tubes.
Time of Collection: Trough, just prior to the next dose.
Record the exact time of specimen collection on the tube or in the computer system.
Physician Office/Draw Specimen Preparation
Let specimens clot 30-60 minutes. Centrifuge specimen to separate serum from cells. Refrigerate (2-8°C or 36-46°F) the centrifuged collection tube within two hours of collection. (Minimum: 0.5 mL serum)
Preparation for Courier Transport
Transport: Centrifuged collection tube, refrigerated (2-8°C or 36-46°F). (Minimum: 0.5 mL serum)
- Serum Separator (SST) tubes.
- Severely lipemic or hemolyzed specimens.
Let specimens clot 30-60 minutes. Centrifuge specimen to separate serum from cells. Deliver immediately to the appropriate testing station.
Specimen Stability for Testing:
Room Temperature (20-26°C or 68-78.8°F): 24 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): 3 months
Specimen Storage in Department Prior to Disposal:
Frozen (-20°C/-4°F or below): 2 months
Royal Oak Toxicology Laboratory
Results available the same day as testing performed (1-4 days).
Doxepin + Nordoxepin: 75-200 ng/mL.
Critical: Greater than 500 ng/mL total.
Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS).
This test was developed and its performance characteristics determined by Beaumont Health. It has not been cleared or approved by the FDA. The Laboratory is regulated under CLIA as qualified to perform high-complexity testing. This test is used for clinical purposes and should not be regarded as investigational or for research.
Tricyclic antidepressants can display cardiotoxicity in the elderly and susceptible adults and children.
This assay is used to monitor the therapeutic drug level and evaluate the toxicity of doxepin. Doxepin is a tricyclic antidepressant used to treat depression. Nordoxepin is the major active metabolite of doxepin.
80337 (alternate: G0480).
LOINC: 3582-4, Doxepin 3579-0, 61415-6, Nordoxepin 3862-0, 58014-2, Doxepin Plus Nordoxepin 3582-4
Toxicology Laboratory – RO
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