Triples with object Enzyme system: human liver microsomes: NADPH added: not mentioned but acceptable methods assumed inhibitor used: quinidine reaction: risperidone 9-hydroxylation NOTE: experiment used 100micM of risperidone which is likely well above C_max based on PMID 7690693 Quote: risperidone was incubated with human liver microsomes in the presence of different concentrations of inhibitors of CYP enzymes. Both quinidine (inhibitor of CYP2D6) and ketoconazole (inhibitor of CYP3A) inhibited the formation of 9-hydroxyrisperidone in a concentration-dependent manner (Fig. 4).