Test Name: Amitriptyline/Nortriptyline
Health Link Test Code: XAMIT
LIS Test Code: AMTP
CPT Code(s): 80335
Amitriptyline and its major active metabolite, nortriptyline.
Methodology: Liquid Chromatography
Days Performed: Mon-Fri, dayshift.
In-Lab Turnaround Time: 2 - 3 days.
Patient should be on the same dose for at least five days before collecting drug level.
Collection Container: Red top
Collect specimen for trough level prior to next dose.
Collection Volume: 4 mL
Pediatric Collection Volume: 4 mL
Sample Analyzed: Serum
Testing Volume: 2 mL
Pediatric Testing Volume: 1.5 mL
Centrifuge. Transfer cell-free serum to plastic vial. Refrigerate.
Transport specimen to laboratory. Transport with coolant pack if coming from clinic location.
Specimens collected in red cap with yellow ring (SST) tubes are not acceptable.
|Generally effective therapeutic concentration:|
|18 years and up:||Amitriptyline plus nortriptyline||120-250 ng/mL|
|18 years and up:||Total tricyclic antidepressant concentration in excess of 500 ng/mL|
Interpretation Type: Interpretive Guidelines
Critical Calls: yes
Result of "BELOW DETECTION" indicates that the result is below the method detection limit of 10 ng/mL. The half-life of nortriptyline in an adult is 18-93 hours. It is the major metabolite of amitriptyline (Elavil). Nortriptyline may enhance the effects of alcohol, barbiturates, and other CNS depressants.
This test was developed and its performance characteristics determined by the UWHC Clinical Laboratories. This test meets the standards for clinical testing. This test should not be regarded as investigational or for research use. The US Food and Drug Administration (FDA) has not approved or cleared this test; however, the FDA has determined that such clearance or approval is not necessary.