A synthetic phenethylamine bicyclic derivative with antidepressant activity. Venlafaxine and its active metabolite, O-desmethylvenlafaxine (ODV), are potent inhibitors of neuronal serotonin and norepinephrine reuptake and weak dopamine reuptake inhibitors. This agent may reduce hormone-related vasomotor symptoms. Check for active clinical trialsusing this agent. OR A drug used to treat depression and certain anxiety disorders. It may also be used to treat hot flashes in women who are in menopause or are being treated for breast cancer. Venlafaxine increases the levels of the chemicals serotonin and norepinephrine in the brain, which helps improve mood. It is a type of antidepressant and a type of serotonin-norepinephrine reuptake inhibitor. Also called Effexor.