Tricyclic Antidepressants Screen, Serum or Plasma

CPT: 80337
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Test Includes

Amitriptyline/nortriptyline; doxepin/nordoxepin; imipramine/desipramine

Special Instructions

Specify drug ingested.

Expected Turnaround Time

2 - 4 days

Specimen Requirements


Serum or plasma


2 mL

Minimum Volume

0.6 mL


Red-top tube, lavender-top (EDTA) tube, or green-top (heparin) tube. Do not use a gel-barrier tube. The use of gel-barrier tubes is not recommended due to slow absorption of the drug by the gel. Depending on the specimen volume and storage time, the decrease in drug level due to absorption may be clinically significant.


Transfer separated serum or plasma to a plastic transport tube.

Storage Instructions


Stability Requirements



Room temperature

3 days


1 month


3 months

Causes for Rejection

Gel-barrier tube

Test Details


Detect the presence of tricyclic antidepressants


This test was developed, and its performance characteristics determined, by LabCorp. It has not been cleared or approved by the US Food and Drug Administration (FDA).


Liquid chromatography/tandem mass spectrometry (LC/MS-MS)

Reference Interval

Negative (<20 ng/mL)

Additional Information

Tricyclic antidepressants are prescribed for the treatment of endogenous depression and neuralgic pain disorders. The tricyclic antidepressants include amitriptyline, imipramine, doxepin, and their demethylated metabolites, nortriptyline and desipramine. The tricyclic antidepressants block neuronal uptake of norepinephrine and serotonin. The degree of inhibition seems to correlate with antidepressant activity. These drugs also have sedative effects.1


1. Burtis CA, Ashwood ER, Bruns DE, eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 4th ed. St Louis, Mo: Elsevier Saunders; 2005:1309.


Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
007690 Tricyclic Antidepressants 10552-8 072413 Amitriptyline ng/mL 3333-2
007690 Tricyclic Antidepressants 10552-8 700088 Nortriptyline ng/mL 3872-9
007690 Tricyclic Antidepressants 10552-8 700089 Total (Ami+Nor) ng/mL 3335-7
007690 Tricyclic Antidepressants 10552-8 072439 Imipramine ng/mL 3690-5
007690 Tricyclic Antidepressants 10552-8 700104 Desipramine ng/mL 3531-1
007690 Tricyclic Antidepressants 10552-8 700105 Total (Imi+Des) ng/mL 9627-1
007690 Tricyclic Antidepressants 10552-8 072421 Doxepin ng/mL 3579-0
007690 Tricyclic Antidepressants 10552-8 700096 Nordoxepin ng/mL 3862-0
007690 Tricyclic Antidepressants 10552-8 700097 Total Dox+Nordox ng/mL 3582-4
007690 Tricyclic Antidepressants 10552-8 700472 Disclaimer: N/A

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