(±)-N-desmethyl Venlafaxine is a minor active metabolite of the selective norepinephrine and serotonin reuptake inhibitor (SNRI) venlafaxine.1 It is formed from venlafaxine by the cytochrome P450 (CYP) isoform CYP3A4.2 (±)-N-desmethyl Venlafaxine inhibits norepinephrine and serotonin reuptake in rat synaptosome preparations (IC50s = 4.7 and 1.6 µM, respectively).1 In vivo, (±)-N-desmethyl venlafaxine reverses reserpine-induced hypothermia in mice with a minimum effective dose (MED) of 10 mg/kg.
1.Muth, E.A., Moyer, J.A., Haskins, J.T., et al.Biochemical, neurophysiological, and behavioral effects of Wy-45,233 and other identified metabolites of the antidepressant venlafaxineDrug Dev. Res.23(2)191-199(1991) 2.Otton, S.V., Ball, S.E., Cheung, S.W., et al.Venlafaxine oxidation in vitro is catalysed by CYP2D6Br. J. Clin. Pharmacol.41(2)149-156(1996)