ARUP's Laboratory Test Directory

Doxepin and Metabolite, Serum or Plasma : 0090102

Mnemonic: DOXEPIN

Methodology: Quantitative Liquid Chromatography-Tandem Mass Spectrometry
Performed: Sun-Sat
Reported: 1-3 days
Specimen Required: Patient Prep: Timing of specimen collection: Pre-dose (trough) draw - At steady state concentration.

Collect: Plain red. Also acceptable: Lavender (K2 or K3EDTA) or pink (K2EDTA).

Specimen Preparation: Separate serum or plasma from cells within 2 hours of collection. Transfer 1 mL serum or plasma to an ARUP Standard Transport Tube. (Min: 0.5 mL)

Storage/Transport Temperature: Refrigerated.

Unacceptable Conditions: Whole blood. Gel separator tubes, light blue (citrate), or yellow (SPS or ACD solution).

Stability (collection to initiation of testing): After separation from cells: Ambient: 5 days; Refrigerated: 2 weeks; Frozen: 6 months
Reference Interval:
Effective February 19, 2013
 
Therapeutic Range Total (doxepin and nordoxepin): 100-300 ng/mL
Toxic Level Greater than 500 ng/mL

Interpretive Data: Toxic concentrations may cause anticholinergic effects and cardiac abnormalities.
CPT Code(s): 80166; 80299
Cross References: Adapin (Doxepin & Metabolite), Nordoxepin (Doxepin & Metabolite), Prudoxin (Doxepin & Metabolite), Sinequan (Doxepin & Metabolite), Zonalon (Doxepin & Metabolite)