American Board of Psychiatry and Neurology (ABPN) Practice Exam 2025 - Free ABPN Practice Questions and Study Guide

Amoxapine is the tricyclic antidepressant in question known for its significant dopamine-blocking activity. While tricyclic antidepressants (TCAs) primarily work by inhibiting the reuptake of serotonin and norepinephrine, amoxapine stands out due to its active metabolite, 7-hydroxyamoxapine, which has potent antipsychotic properties akin to some typical antipsychotics. This dopamine antagonism can contribute to its efficacy in managing depressive symptoms with a potential impact on conditions where dopaminergic pathways are involved.

In contrast, the other tricyclic antidepressants listed do not exhibit significant dopamine-blocking activity through their metabolites. Clomipramine primarily acts on serotonin and norepinephrine without notable dopamine antagonism. Desipramine, while it has a more noradrenergic profile, does not significantly influence dopamine receptors. Similarly, trimipramine, although it has a unique mechanism among TCAs with some atypical characteristics, does not exert substantial dopamine-blocking effects. Thus, amoxapine's unique pharmacological profile accounts for its significant dopamine-blocking activity among the listed options.