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22571 Doxepin and Nordoxepin (DXPIN)

Doxepin and Nordoxepin (DXPIN)
Test Code: DOXSO
Synonyms/Keywords
​Lab Ref Code:  93011, Adapin (Doxepin), Doxepin (Sinequan), Nordox (Doxepin)
Useful For
Monitoring therapy
Evaluating potential toxicity
Evaluating patient compliance
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)
Serum​ ​Red Top Tube (RTT) ​ ​1 mL 0.25 mL ​
Collection Processing Instructions
1. Draw specimen immediately before next scheduled dose (or at a minimum 12 hours after last dose).
2. Serum must be separated from cells within 2 hours of draw.
Specimen Stability Information
Specimen Type Temperature Time
Serum ​ ​ Refrigerated (preferred)​ 28 days
​Ambient 7 days
​Frozen ​28 days
Rejection Criteria
Hemolysis
Mild OK; Gross reject
​Lipemia
Mild OK; Gross reject
​Icterus
Mild OK; Gross reject
​Other ​Serum gel tube
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
Mayo Medical Laboratories​​
Monday through Saturday; Varies
2 days
High-Performance Liquid Chromatography (HPLC)
Reference Lab
Mayo Clinic Laboratories
Reference Range Information
Performing Location Reference Range
Mayo Medical Laboratories​​
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.
Interpretation
Most individuals display optimal response to doxepin when combined serum levels of doxepin and nordoxepin are between 50 and 150 ng/mL. Some individuals may respond well outside of this range, or may display toxicity within the therapeutic range; thus, interpretation should include clinical evaluation. Risk of toxicity is increased with combined levels > or =300 ng/mL.
 
Therapeutic ranges are based on specimens drawn at trough (ie, immediately before the next dose).
Outreach CPTs
CPT Modifier
(if needed)		 Quantity Description Comments
​80335 ​ ​ ​ ​
Synonyms/Keywords
​Lab Ref Code:  93011, Adapin (Doxepin), Doxepin (Sinequan), Nordox (Doxepin)
Ordering Applications
Ordering Application Description
​Centricity ​LAB Doxepin and Nordoxepin (DOXP)
​Cerner ​Doxepin and Nordoxepin Level (DOXP)
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)
Serum​ ​Red Top Tube (RTT) ​ ​1 mL 0.25 mL ​
Collection Processing
1. Draw specimen immediately before next scheduled dose (or at a minimum 12 hours after last dose).
2. Serum must be separated from cells within 2 hours of draw.
Specimen Stability Information
Specimen Type Temperature Time
Serum ​ ​ Refrigerated (preferred)​ 28 days
​Ambient 7 days
​Frozen ​28 days
Rejection Criteria
Hemolysis
Mild OK; Gross reject
​Lipemia
Mild OK; Gross reject
​Icterus
Mild OK; Gross reject
​Other ​Serum gel tube
Useful For
Monitoring therapy
Evaluating potential toxicity
Evaluating patient compliance
Reference Range Information
Performing Location Reference Range
Mayo Medical Laboratories​​
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.
Interpretation
Most individuals display optimal response to doxepin when combined serum levels of doxepin and nordoxepin are between 50 and 150 ng/mL. Some individuals may respond well outside of this range, or may display toxicity within the therapeutic range; thus, interpretation should include clinical evaluation. Risk of toxicity is increased with combined levels > or =300 ng/mL.
 
Therapeutic ranges are based on specimens drawn at trough (ie, immediately before the next dose).
For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
Mayo Medical Laboratories​​
Monday through Saturday; Varies
2 days
High-Performance Liquid Chromatography (HPLC)
Reference Lab
Mayo Clinic Laboratories
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)		 Quantity Description Comments
​80335 ​ ​ ​ ​
For most current information refer to the Marshfield Laboratory online reference manual.