NORTRIPTYLINE - (P)
Test Code: MIS6
Test Indications: Nortriptyline is a tricyclic antidepressant used for treatment of endogenous depression. It also is a metabolite of the antidepressant amitriptyline. Nortriptyline is used when its stimulatory side effect is considered to be of clinical advantage; amitriptyline is used when the side effect of mild sedation is desirable.
Nortriptyline is unique among the antidepressants in that its blood level exhibits the classical therapeutic window effect; blood concentrations above or below the therapeutic window correlate with poor clinical response. Thus, therapeutic monitoring to ensure that the blood level is within the therapeutic window is critical to accomplish successful treatment with this drug.
This test and reference range applies when only nortriptyline is administered. When amitriptyline is administered, please refer to AMITRIPTYLINE
Patient Preparation Instructions: Therapeutic ranges should be determined in specimens drawn at trough immediately before next dose. collect blood within 1 hours prior to next dose or at least 12 hours after last dose.
Do not use separator gel.
Plasma: 2.0 mL
Serum collected without gel is also acceptable.
Serum: 2.0 mL
In-Common Laboratories Reference Values
Within 10 Days
Specimens that are obtained from gel tubes are not acceptable and will be rejected, as the gel absorbs the drugs and will lead to falsely decreased concentrations. Separate plasma or serum as soon as possible and no longer than 2 hours from time of collection and freeze. Send frozen specimens to In-Common Laboratories (Test ID: NORT).