Nortriptyline, Serum
Use
Monitoring nortriptyline concentration during therapy is critical to evaluate potential nortriptyline toxicity and aid in patient compliance. Nortriptyline is a tricyclic antidepressant used for treating endogenous depression and functions by exploiting its stimulatory side effects. Therapeutically, it is essential to monitor blood levels within a therapeutic window to ensure successful treatment outcomes, as concentrations outside this window can correlate with poor clinical response.
Special Instructions
If not ordering electronically, complete, print, and send a Therapeutics Test Request form (T831) with the specimen. Specimens should be collected just before the next scheduled dose, ideally 12 hours after the last dose. Serum should be separated from cells within 2 hours of collection to prevent falsely elevated levels.
Limitations
This test cannot be performed on whole blood. Serum must be separated from cells within 2 hours post-collection. Specimens from gel tubes are not acceptable because the drug may absorb onto the gel, falsely decreasing concentrations. Furthermore, improper specimen handling can lead to diagnostic confusion and inappropriate test selection.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 3872-9
- 3872-9
Result Turnaround Time
3-5 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.25 mL
Container
Plastic vial
Collection Instructions
Collect specimen immediately before next scheduled dose (minimum 12 hours after last dose). Centrifuge and aliquot serum into a plastic vial. Serum must be separated from cells within 2 hours of collection.
Causes for Rejection
Gross hemolysis, gross lipemia, gross icterus.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 28 days |
| Frozen | 28 days |