PILOT-STUDY OF THE CYTOCHROME P450-2D6 GENOTYPE IN A PSYCHIATRIC STATE-HOSPITAL

Objective: The authors conducted a pilot study to develop preliminary data on the frequency of cytochrome P450-2D6 (CYP2D6) genotypes in sta te psychiatric hospital patients and to establish population sizes nee ded to determine potential clinical relevance in therapeutic outcome. Method: One hundred consecutive inpatients at Eastern State Hospital i n Kentucky who provided informed consent were genotyped at the CYP2D6 locus during their hospital stay. Results: Twelve of the patients were CYP2D6 deficient, and four carried the 1Xn or *2Xn allele associated with ultrarapid metabolism; all of these patients were Caucasian (N=8 7). The rate of deficiency in CYP2D6 expression in these Caucasian sta te psychiatric hospital patients (14%) was twice that of the U.S. popu lation (7%). The patients with CYP2D6 deficiency also appeared more li kely to experience side effects in response to CYP2D6 medications. Con clusions: This study, limited by a small number of subjects, suggests that one-fifth of Caucasians admitted to a state hospital in Kentucky had genotypes associated with extremes in CYP2D6 activity that may hav e affected their response to CYP2D6 medications.