Mechanism of Action Trazodone HCl Tab, Trazodone is an antidepressant that belongs to the class of serotonin antagonist and reuptake inhibitors (SARIs). It works by increasing the levels of serotonin, a neurotransmitter that helps regulate mood, by inhibiting its reuptake and blocking certain serotonin receptors. This dual action helps improve mood and relieve symptoms of depression and anxiety...