title: CYP2D6 genotyping with oligonucleotide microarrays and nortriptyline concentrations in geriatric depression.
abstract: Recent advances in oligonucleotide microarray technology ("gene chips") permit rapid screening for DNA sequence variation. The CYP2D6 gene encodes debrisoquine hydroxylase, which metabolizes the antidepressant nortriptyline and other psychotropic medications. Nortriptyline plasma concentrations were obtained after at least three weeks of treatment in 36 geriatric patients with major depression who were taking a mean of 8.6 other medications besides nortriptyline. Oligonucleotide microarrays were used to detect 16 CYP2D6 alleles that affect debrisoquine hydroxylase activity. Subjects carrying alleles encoding impaired debrisoquine hydroxylase activity had significantly greater nortriptyline concentrations and lower nortriptyline doses than did other subjects. Significant correlations were found between the numbers of alleles encoding decreased metabolism and nortriptyline plasma concentration, nortriptyline dose, and nortriptyline plasma concentration standardized for dose, indicating a gene dosage effect. These results demonstrate that CYP2D6 genotyping on a microarray platform can be used to predict plasma antidepressant concentrations despite advanced patient age and numerous concurrent medications.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, MSLS P-104, Stanford University School of Medicine, Stanford, CA 94305-5485, USA. gmurphy@leland.stanford.edu
authors.forename: G M
authors.initials: GM
authors.lastname: Murphy
authors.forename: B G
authors.initials: BG
authors.lastname: Pollock
authors.forename: M A
authors.initials: MA
authors.lastname: Kirshner
authors.forename: N
authors.initials: N
authors.lastname: Pascoe
authors.forename: W
authors.initials: W
authors.lastname: Cheuk
authors.forename: B H
authors.initials: BH
authors.lastname: Mulsant
authors.forename: C F
authors.initials: CF
authors.lastname: Reynolds
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D000929:Antidepressive Agents, Tricyclic / Q000009:adverse effects / Q000493:pharmacokinetics* / Q000627:therapeutic use*; D019389:Cytochrome P-450 CYP2D6 / Q000235:genetics*; D003866:Depressive Disorder / Q000188:drug therapy* / Q000523:psychology; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D009661:Nortriptyline / Q000009:adverse effects / Q000493:pharmacokinetics* / Q000627:therapeutic use*; D020411:Oligonucleotide Array Sequence Analysis; D009841:Oligonucleotides / Q000737:chemistry*
chemical_list: D000929:Antidepressive Agents, Tricyclic; D009841:Oligonucleotides; D009661:Nortriptyline; D019389:Cytochrome P-450 CYP2D6