The University of Iowa (UIHC)
Department of Pathology
LABORATORY SERVICES HANDBOOK


Tricyclic Antidepressant Toxicology Screen (TCA)
Order Code: TCAS
Order Form: A-1a Therapeutic Drug Analysis or IPR Req
  Chemistry
6240 RCP
356-3527
Specimen
Serum
Collection Medium:
Red top tube
Alternate
Collection Media:
Call laboratory for additional acceptable specimen collection 
containers.
Minimum:
5 mL in red top tube or two red top microtubes
Rejection Criteria:
Gel separator tubes.
Testing Schedule:
24 hrs/day, 7 days a week, including holidays.
Analytic Time:
3 hours (upon receipt in laboratory)
Reference Range:
Positive result:  Possible toxic concentration > or = to 300 ng/ml
Negative result:  None or therapeutic concentration < 300 ng/ml
Comments:
Semiquantitative non-specific immunological test for toxicological 
detection of TCA exposure.  It will detect primarily the four major 
TCA's:  Amitriptylline, Nortriptyline, Imipramine and Desipramine.  
Samples containing other TCA's, phenothiazines, or drugs structurally 
related to TCA may show interference in the assay.
Test
Limitations:
The Tricyclic Antidepressants assay is primarily for the detection of 
the four major TCA: Amitriptyline, nortriptyline, imipramine and 
desipramine.  Applicability of the assay to other TCA must be 
interpreted based upon their relative cross-reactivities.  Refer to the 
Specificity section in this assay insert for additional information.  
The concentration reading of a serum or plasma sample is only an 
estimation of the total amount of TCA and their demethylated 
metabolites present.  Accurate quantitation of total TCA or individual 
TCA should be determined by a confirmatory assay methodology such as 
HPLC or GC.  Samples containing toxic concentrations of phenothiazines 
such as perphenazine, or other drugs structurally related to TCA, such 
as cyclobenzaprine, may show interference in the assay.  Seroquel, 
Clozaril, Ludiomil and Remeron have been shown to cross-react.
Methodology:
Fluorescent Polarization ImmunoAssay (FPIA)
CPT Code:
80101
 
See also:
Amitriptyline/Nortriptyline Fractionation, Serum
Drugs of Abuse Screen, Urine
Imipramine/Desipramine Fractionation, Serum
 
See Additional Information:
Chemistry Critical Lab Values

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Updated: 07/14/2008

Note: The information contained in this handbook is for use by personnel of University of Iowa Health Care. No other use is implied or intended.