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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, S

Specimen Type

Serum Red


Specimen Required


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 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 drawn at trough (ie, immediately before next scheduled dose). Levels may be elevated in non-trough specimens.

Day(s) Performed

Monday, Wednesday, Friday

Report Available

2 to 5 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

80335

G0480 (if appropriate)

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.