Test Code DOXEPM Doxepin and Nordoxepin, Serum
Additional Codes
MAYO: DXPIN
EPIC: LAB146
Useful For
Monitoring doxepin therapy
Evaluating potential doxepin toxicity
Evaluating patient compliance
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Reporting Name
Doxepin and Nordoxepin, SSpecimen Type
Serum RedSpecimen Required
Supplies: Sarstedt Aliquot Tube 5 mL (T914)
Collection Container/Tube: Red top (Serum gel/SST are not acceptable)
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions:
1. Collect specimen immediately before next scheduled dose (minimum 12 hours after last dose).
2. Centrifuge and aliquot serum into a plastic vial. Serum must be separated from cells within 2 hours of collection.
Specimen Minimum Volume
0.25 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum Red | Refrigerated (preferred) | 28 days | |
Frozen | 28 days | ||
Ambient | 7 days |
Reject Due To
Gross hemolysis | Reject |
Gross lipemia | Reject |
Gross icterus | Reject |
Reference Values
Therapeutic concentration (doxepin + nordoxepin): 50-150 ng/mL
Note: Therapeutic ranges are for specimens collected at trough (ie, immediately before next scheduled dose). Levels may be elevated in non-trough specimens.
Day(s) Performed
Tuesday, Thursday, Sunday
Report Available
3 to 5 daysPerforming Laboratory
Mayo Clinic Laboratories in RochesterTest Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
80299
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
DXPIN | Doxepin and Nordoxepin, S | 43122-1 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
63507 | Doxepin | 3579-0 |
37125 | Nordoxepin | 3862-0 |
37126 | Doxepin and Nordoxepin | 3582-4 |
Forms
If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.