Inadequate/Extensive Metabolizers, CYP2D6 The development of the active metabolite, M1, is mediated by CYP2D6, a polymorphic enzyme. Somewhere around 7% on the inhabitants has lowered activity on the CYP2D6 isoenzyme of cytochrome P450 metabolizing enzyme method. These men and women are “very poor metabolizers” of debrisoquine, dextromethorphan and tricyclic antidepressants, https://waldog543uem3.wikiconverse.com/user