Sheep Anti-Venlafaxine polyclonal antibody for ELISA, WB, Dot, IHC, IA, LFIA. Venlafaxine — brand names: Effexor, Effexor XR, Lanvexin, Viepax and Trevilor — is an antidepressant of the serotonin-norepinephrine reuptake inhibitor (SNRI) class.[3][4][5] This means it increases the concentrations of the neurotransmitters serotonin and norepinephrine in the body and the brain. First introduced by Wyeth in 1993, now marketed by Pfizer, it is licensed for the treatment of major depressive disorder (MDD), generalised anxiety disorder (GAD), panic disorder and social phobia.