Paroxetine is a selective serotonin reuptake inhibitor. It is used to manage major depressive disorder, panic disorder, OCD, social phobia, generalized anxiety disorder, the vasomotor symptoms of menopause, and premenstrual dysphoric disorder. Paroxetine selectively binds to the sodium dependent serotonin transporter (SERT) and blocks the recycling of serotonin from the synapse. As serotonin accumulates it enhances the serotonergic function of the 5-hydroxytryptamine 1A receptor leading to decreased anxiety and depressive moods. Lower serotonin concentrations in a depressed brain induces the upregulation of serotonergic receptors therefore by increasing the concentration of serotonin in the synapse, paroxetine in turn induces down regulation of the former upregulated serotonin receptors thereby restoring receptor concentration. Paroxetine has demonstrated a stronger inhibitory effect on serotonin reuptake than other members of the same drug class, including Citalopram, Fluoxetine, and Fluvoxamine.

Paroxetine Mechanism of Action Pathway (New) References