Which of the following medications is NOT a tertiary amine TCA?

Duloxetine is not classified as a tertiary amine tricyclic antidepressant (TCA) because it is a selective serotonin and norepinephrine reuptake inhibitor (SNRI). Unlike tertiary amine TCAs, which primarily act on norepinephrine and serotonin but often have a broader range of side effects due to their influence on other neurotransmitter systems, Duloxetine has a more focused mechanism of action. Specifically, it primarily inhibits the reuptake of serotonin and norepinephrine without the additional anticholinergic and sedative effects commonly associated with tertiary amines. This makes it a more modern treatment approach for depression and anxiety disorders, distinguishing it from the older generation of TCAs.

In contrast, Imipramine, Doxepin, and Trimipramine are all classified as tertiary amine TCAs. They have a more complex pharmacological profile, which includes varying degrees of sedative and anticholinergic side effects, and are used in different clinical situations based on their properties.