Risperidone metabolic ratio as a biomarker of individual CYP2D6 genotype in schizophrenic patients
- 421 Downloads
The purpose of the present study was to investigate the predictive value of the risperidone metabolic ratio for the individual CYP2D6 genotype.
The determination of risperidone, 9-hydroxyrisperidone, and CYP2D6 genotype was performed in 89 schizophrenic patients. The receiver operator characteristic (ROC) method and the area under the ROC curve (AUC) were used to illustrate the predictive value of risperidone metabolic ratio for the individual CYP2D6 genotype. The area under the ROC curve (AUC) was used as a global measure of this predictive value. To evaluate the proposed cutoff levels of >1 and <0.1 to identify individuals with a poor or ultrarapid CYP2D6 genotype the sensitivity, specificity, positive predictive value and negative predictive were calculated.
The area under the ROC curve (AUC) for poor and ultrarapid metabolisers was 0.85 and 0.86, respectively. The sensitivity, specificity, positive predictive value and negative predictive value of a risperidone/9–OH-risperidone ratio >1 to CYP2D6 poor metaboliser genotype were 75 %, 95 %, 60 % and 97 %, respectively. The corresponding measures for a metabolic ratio < 0.1 to predict ultrarapid metabolisers were 80 %, 77 %, 18 % and 98 %.
A metabolic ratio > 1 or < 0.1 may be a useful therapeutic biomarker to recommend CYP2D6 genetic testing to guide the present or future treatment of patients in need of psychotropic drugs.
KeywordsCYP2D6 genotype Genetic polymorphism Therapeutic drug monitoring Psychotropic drugs
The work was supported financially by the Swedish Society for Medical Research, Stockholm County Council and Karolinska Institutet. We wish to thank Dr Jonatan Lindh for valuable input on data presentation and comments on the manuscript.
Declaration of potential conflicts of interest
The authors declare no conflicts of interest.
- 18.Flockhart, D., Drug interactions: Cytochrome P450 Drug Interaction Table. Indiana School of Medicine 2007. Available at: http://medicine.iupui.edu/flockhart/table.htm Accessed August 28, 2013.