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Test Code DXPIN Doxepin and Nordoxepin, Serum

Reporting Name

Doxepin and Nordoxepin, S

Useful For

Monitoring doxepin therapy

 

Evaluating potential doxepin toxicity

 

Evaluating patient compliance

Method Name

Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Serum Red


Specimen 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

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

Report Available

3 to 5 days

Test 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.

NY State Approved

Yes

Forms

If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.