High Quality Content by WIKIPEDIA articles! Desvenlafaxine (brand name: Pristiq), also known as O-desmethylvenlafaxine, is an antidepressant of the serotonin-norepinephrine reuptake inhibitor class developed and marketed by Wyeth (now part of Pfizer). Desvenlafaxine is a synthetic form of the major active metabolite of venlafaxine (sold under the brand names Effexor and Efexor). It is being targeted as the first non-hormonal based treatment for menopause.