(Z)-10-Hydroxynortriptyline -d 3 is the deuterium labeled (Z)-10-Hydroxynortriptyline. (Z)-10-Hydroxynortriptyline is a metabolite of Nortriptyline. Nortriptyline is a tricyclic antidepressant and the main active metabolite of Amitriptyline, and is used to relieve the symptoms of depression.