Notes: Aripiprazole N-oxide is a metabolite of the atypical antipsychotic aripiprazole (Item No. 19989).{61450,68114} It is formed from aripiprazole by the cytochrome P450 (CYP) isoforms CYP2D6 and CYP3A4.{68115} Aripiprazole N-oxide is a potential impurity found in commercial preparations of aripiprazole.{61450}