benefit in hastening the removal of venlafaxine, due to the drug's high volume of distribution . [ 48 ] Mechanism of action Venlafaxine is a bicyclic antidepressant, and is usually categorized as a serotonin-norepinephrine reuptake inhibitor (SNRI), but it has been referred to as a serotonin-norepinephrine-dopamine reuptake inhibitor . [ 49