This blood test is used to detect Tricyclic Antidepressants (TCAs). Tricyclic antidepressants have a potential for abuse. The Tricyclic Antidepressants screen includes testing for the following antidepressant drug categories: Amitriptyline/nortriptyline Doxepin/nordoxepin Imipramine/desipramine (Tofranil)TCAs can be detected for up to 7 days after initially taken.