Atomoxetine is the first non-stimulant drug for the treatment of children and adults with attention deficit hyperactivity disorder (ADHD), and its safety and efficacy show significant differences in the pediatric population. This article reviews the genetic factors influencing the pharmacokinetic differences of atomoxetine from the aspect of the gene polymorphisms of the major metabolizing enzyme CYP2D6 of atomoxetine, and then from the perspective of therapeutic drug monitoring, this article summarizes the reference ranges of the effective concentration of atomoxetine in children with ADHD proposed by several studies. In general, there is an association between the peak plasma concentration of atomoxetine and clinical efficacy, but with a lack of data from the Chinese pediatric population. Therefore, it is necessary to establish related clinical indicators for atomoxetine exposure, define the therapeutic exposure range of children with ADHD in China, and combine CYP2D6 genotyping to provide support for the precision medication of atomoxetine.
Adult ; Child ; Humans ; Adrenergic Uptake Inhibitors/therapeutic use* ; Atomoxetine Hydrochloride/therapeutic use* ; Attention Deficit Disorder with Hyperactivity/genetics* ; Cytochrome P-450 CYP2D6/therapeutic use* ; Drug Monitoring ; Genetic Testing ; Propylamines/therapeutic use* ; Treatment Outcome

Pharmacogenetic testing for clinical applications is steadily increasing. Correct and adequate use of pharmacogenetic tests is important to reduce unnecessary medical costs and adverse patient outcomes. This document contains recommended pharmacogenetic testing guidelines for clinical application, interpretation, and result reporting through a literature review and evidence-based expert opinions for the clinical pharmacogenetic testing covered by public medical insurance in Korea. This document aims to improve the utility of pharmacogenetic testing in routine clinical settings.
Anticoagulants/therapeutic use ; Antidepressive Agents/therapeutic use ; Antimetabolites, Antineoplastic/therapeutic use ; Antitubercular Agents/therapeutic use ; Arylamine N-Acetyltransferase/genetics ; Coronary Artery Disease/drug therapy/genetics ; Cytochrome P-450 CYP2C19/genetics ; Cytochrome P-450 CYP2C9/genetics ; Cytochrome P-450 CYP2D6/genetics ; Depressive Disorder/drug therapy/genetics ; Genotype ; Isoniazid/therapeutic use ; Laboratories, Hospital/standards ; Methyltransferases/genetics ; Pharmacogenomic Testing/*methods/standards ; Platelet Aggregation Inhibitors/therapeutic use ; Pulmonary Embolism/drug therapy/genetics ; Ticlopidine/analogs & derivatives/therapeutic use ; Tuberculosis/drug therapy/genetics ; Vitamin K Epoxide Reductases/genetics ; Warfarin/therapeutic use

CYP2D6 is primarily responsible for the metabolism of clomiphene citrate (CC). The purpose of the present study was to investigate the relationship between CYP2D6 genotypes, concentrations of CC and its major metabolites and drug response in infertility patients. We studied 42 patients with ovulatory dysfunction treated with only CC. Patients received a dose of 100 mg/day CC on days 3-7 of the menstrual cycle. CYP2D6 genotyping and measurement of CC and the major metabolite concentrations were performed. Patients were categorized into CC responders or non-responders according to one cycle response for the ovulation. Thirty-two patients were CC responders and 10 patients were non-responders with 1 cycle treatment. The CC concentrations were highly variable within the same group, but non-responders revealed significantly lower (E)-clomiphene concentration and a trend of decreased concentrations of active metabolites compared to the responders. Nine patients with intermediate metabolizer phenotype were all responders. We confirmed that the CC and the metabolite concentrations were different according to the ovulation status. However, our results do not provide evidence for the contribution of CYP2D6 polymorphism to either drug response or CC concentrations.
Adult ; Chromatography, High Pressure Liquid ; Clomiphene/blood/metabolism/*therapeutic use ; Cytochrome P-450 CYP2D6/*genetics ; Estrogen Antagonists/analysis/metabolism/therapeutic use ; Female ; Genotype ; Humans ; Infertility/*drug therapy/genetics ; Ovulation Induction ; Phenotype ; *Polymorphism, Genetic ; Republic of Korea ; Tandem Mass Spectrometry

PURPOSE: Nonresponse to any selective serotonin reuptake inhibitor (SSRI) treatment is rare. In this study, we aimed to investigate ejaculation delay nonresponse to paroxetine treatment in men with lifelong premature ejaculation (PE) who were also known to be nonresponders to other SSRIs. MATERIALS AND METHODS: Five males with lifelong PE who were known nonresponders to paroxetine and other serotonergic antidepressants and eight males with lifelong PE who were specifically recruited were included. Blood sampling occurred 1 month and 1 day before the start of treatment and at the end of three consecutive series of 4 weeks of daily treatment with 10-, 20-, and 30-mg paroxetine, respectively. Blood samples for measurement of leptin and paroxetine were taken at 8:30 AM, 9:30 AM, 10:30 AM, and 11:30 AM, respectively. At 9:00 AM, one tablet of 10-, 20-, or 30-mg paroxetine was taken during the first, second, and third month, respectively. Intravaginal ejaculatory latency time (IELT) was measured with a stopwatch. The main outcome measures were the fold increase in the geometric mean IELT, serum leptin and paroxetine concentrations, body mass index (BMI), 5-HT1A receptor C-1019G polymorphism, and CYP2D6 mutations. RESULTS: Between the 7 paroxetine responders and 6 nonresponders, the fold increase in the geometric mean IELT was significantly different after daily 10-mg (p=0.003), 20-mg (p=0.002), and 30-mg paroxetine (p=0.026) and ranged from 2.0 to 8.8 and from 1.1 to 1.7, respectively. BMI at baseline and at the end of the study was not significantly different between responders and nonresponders. Serum leptin levels at baseline were similar in responders and nonresponders and did not change during treatment. The serum paroxetine concentration increased with increasing dosage and was not significantly different between responders and nonresponders. There was no association between the fold increase in the geometric mean IELT and serum paroxetine levels during the three treatment periods nor between leptin levels during the treatment periods and serum paroxetine levels. For the 5-HT1A receptor C-1019G variation, all responders had the CC genotype and all nonresponders had the GC genotype, respectively. CONCLUSIONS: Complete absence of paroxetine-induced ejaculation delay is presumably related to pharmacodynamic factors and perhaps to 5-HT1A receptor gene polymorphism.
Adolescent ; Adult ; Aged ; Body Mass Index ; Cytochrome P-450 CYP2D6/genetics ; Humans ; Leptin/blood ; Male ; Middle Aged ; Mutation ; Paroxetine/*administration & dosage/blood ; Polymorphism, Genetic ; Premature Ejaculation/*drug therapy/genetics ; Receptor, Serotonin, 5-HT1A/genetics ; Risk Factors ; Serotonin Uptake Inhibitors/*administration & dosage ; Time Factors ; Treatment Outcome ; Young Adult

PURPOSE: Nonresponse to any selective serotonin reuptake inhibitor (SSRI) treatment is rare. In this study, we aimed to investigate ejaculation delay nonresponse to paroxetine treatment in men with lifelong premature ejaculation (PE) who were also known to be nonresponders to other SSRIs. MATERIALS AND METHODS: Five males with lifelong PE who were known nonresponders to paroxetine and other serotonergic antidepressants and eight males with lifelong PE who were specifically recruited were included. Blood sampling occurred 1 month and 1 day before the start of treatment and at the end of three consecutive series of 4 weeks of daily treatment with 10-, 20-, and 30-mg paroxetine, respectively. Blood samples for measurement of leptin and paroxetine were taken at 8:30 AM, 9:30 AM, 10:30 AM, and 11:30 AM, respectively. At 9:00 AM, one tablet of 10-, 20-, or 30-mg paroxetine was taken during the first, second, and third month, respectively. Intravaginal ejaculatory latency time (IELT) was measured with a stopwatch. The main outcome measures were the fold increase in the geometric mean IELT, serum leptin and paroxetine concentrations, body mass index (BMI), 5-HT1A receptor C-1019G polymorphism, and CYP2D6 mutations. RESULTS: Between the 7 paroxetine responders and 6 nonresponders, the fold increase in the geometric mean IELT was significantly different after daily 10-mg (p=0.003), 20-mg (p=0.002), and 30-mg paroxetine (p=0.026) and ranged from 2.0 to 8.8 and from 1.1 to 1.7, respectively. BMI at baseline and at the end of the study was not significantly different between responders and nonresponders. Serum leptin levels at baseline were similar in responders and nonresponders and did not change during treatment. The serum paroxetine concentration increased with increasing dosage and was not significantly different between responders and nonresponders. There was no association between the fold increase in the geometric mean IELT and serum paroxetine levels during the three treatment periods nor between leptin levels during the treatment periods and serum paroxetine levels. For the 5-HT1A receptor C-1019G variation, all responders had the CC genotype and all nonresponders had the GC genotype, respectively. CONCLUSIONS: Complete absence of paroxetine-induced ejaculation delay is presumably related to pharmacodynamic factors and perhaps to 5-HT1A receptor gene polymorphism.
Adolescent ; Adult ; Aged ; Body Mass Index ; Cytochrome P-450 CYP2D6/genetics ; Humans ; Leptin/blood ; Male ; Middle Aged ; Mutation ; Paroxetine/*administration & dosage/blood ; Polymorphism, Genetic ; Premature Ejaculation/*drug therapy/genetics ; Receptor, Serotonin, 5-HT1A/genetics ; Risk Factors ; Serotonin Uptake Inhibitors/*administration & dosage ; Time Factors ; Treatment Outcome ; Young Adult

<p>BACKGROUNDMany studies indicated the human cytochrome P450 2D6 (CYP2D6) gene polymorphism was associated with acute leukemia (AL) susceptibility, however, the results were inconsistent. So we performed this meta-analysis to evaluate the relationship between CYP2D6*3 or CYP2D6*4 polymorphism and AL susceptibility.p><p>METHODSWe searched PubMed database up to February 20, 2013, and finally yielded 9 case-control studies including 1343 cases and 1843 controls which tested the association between CYP2D6*3 or *4 polymorphism and AL. After data extraction, we conducted a meta-analysis using the Comprehensive Meta Analysis software.p><p>RESULTSOverall, no significant association between CYP2D6*3 or *4 polymorphism and AL risk was found in this metaanalysis (+ vs. -: OR = 1.13, 95% CI = 0.79-1.63; +/+ vs. -/-: OR = 1.73, 95% CI = 0.99-3.02; -/+ vs. -/-: OR = 1.03, 95% CI = 0.68-1.56; (-/+ and +/+) vs. -/-: OR = 1.08, 95% CI = 0.72-1.63; +/+ vs. (-/+ and -/-): OR = 1.76, 95% CI = 0.98-3.17). Similar results were also been found in stratified subgroup analysis. There was no publication bias.p><p>CONCLUSIONCYP2D6*3 or *4 polymorphism might not be associated with AL susceptibility. However, the results need to be further confirmed by well-designed and high quality randomized controlled trials with larger sample sizes.p>
Acute Disease ; Cytochrome P-450 CYP2D6 ; genetics ; Genetic Predisposition to Disease ; Humans ; Leukemia ; etiology ; genetics ; Polymorphism, Genetic ; Risk

The aim of the study was to evaluate the association between genetic polymorphisms of CYP2D6 and outcomes in breast cancer patients with tamoxifen treatment. We evaluated the CYP2D6 genetic polymorphisms in 766 breast cancer patients. Among them, 110 patients whose samples were prospectively collected before surgery and treated with tamoxifen were included to evaluate the association between CYP2D6 and outcomes. The genotypes of CYP2D6 were categorized as extensive metabolizer (EM), intermediate metabolizer (IM), and poor metabolizer (PM) according to the activity score. The clinicopathologic features of 110 patients were not significantly different among the three groups except for the T-stage and nodal status. The high T-stage and axillary metastasis were more frequent in the PM group. While recurrence-free and overall survival in the PM group was poorer than the other groups, there was no significant difference between the EM and the IM group. The difference between the PM and the other groups on univariate analysis disappeared on multivariate analysis. These conflicting results suggest that the clinical value of CYP2D6 polymorphisms is still unclear and more large-sized and comprehensively designed trials are necessary.
Adult ; Aged ; Aged, 80 and over ; Antineoplastic Agents, Hormonal/*therapeutic use ; Breast Neoplasms/drug therapy/*genetics/mortality ; Cytochrome P-450 CYP2D6/*genetics ; Female ; Genotype ; Humans ; Kaplan-Meier Estimate ; Middle Aged ; Neoplasm Staging ; *Polymorphism, Single Nucleotide ; Tamoxifen/*therapeutic use

This study is to compare the influence of CYP2D6 *3 and *4 genotypes and phenotypes on the metabolic activity of CYP2D6 in Chinese Han, Uygur and Kazakh ethnic groups. Allele specific amplification (ASA) was used to determine the CYP2D6*3 and CYP2D6*4 genotypes. Phenotypes of CYP2D6 in all subjects were determined using dextromethorphan as probe drug by HPLC methods. Among the 132 Han subjects, one subject (0.76%) exhibited the *1/*3 combination, and one (0.76%) exhibited the *1/*4. Among the 136 Uygur subjects, 4 subjects (2.94%) showed the *1/*3 combination, 12 (8.82%) showed *1/*4, 4 (2.94%) showed *4/*4, and one (0.74%) showed *3/*4. Among the 116 Kazakh subjects, 2 (1.72%) exhibited the *1/*3 combination, 7 (6.03%) exhibited *1/1*4, and one (0.86%) showed *4/*4. This research revealed significant differences in the occurrence frequencies of the CYP2D6 genotype between Han and Uygur ethnic groups, as well as between Uygur and Kazakh populations. However, no difference was found between Han and Kazakh populations. In addition, the prevalence of PMs of the Uygur is comparable to that of the Caucasians. However, the molecular mechanism underlying the poor metabolism is different in these two populations.
Adolescent ; Adult ; Asian Continental Ancestry Group ; classification ; genetics ; China ; ethnology ; Chromatography, High Pressure Liquid ; methods ; Cytochrome P-450 CYP2D6 ; genetics ; Dextromethorphan ; pharmacokinetics ; Female ; Gene Frequency ; Genotype ; Humans ; Male ; Minority Groups ; Phenotype ; Young Adult

CYP2D6 is an important drug-metabolizing enzyme. The polymorphism of CYP2D6 leads to metabolism difference and the different reactions of drugs in the individuals and different races are normal phenomenon in clinical medication. CYP2D6*10 is an important subtype in Asian people and 51.3% Chinese are classified with this subtype. To obtain recombinant active CYP2D6*1/CYP2D6*10 in baculovirus system by optimizing coexpression with CYPOR, and detect their activity to catalyze dextromethorphan, three recombinants pFastBac-CYP2D6*1, pFastBac-CYP2D6*10 and pFastBac-CYPOR were constructed and transformed into DH10Bac cell to obtain the recombinant Bacmid-CYPOR, Bacmid-CYP2D6*1 and Bacmid-CYP2D6*10. And then the recombinant CYP2D6*1 and CYP2D6*10 virus were obtained by transfecting Sf9. Then homogenate protein activity was determined with dextromethorphan as substrate. The multiple of infection (MOI) and its ratio of recombinant CYP2D6 virus to CYPOR virus were adjusted by detecting the activity of the homogenate protein. The Km and Vmax are 26.67 +/- 2.71 micromol x L(-1) (n=3) and 666.7 +/- 56.78 pmol x nmol(-1) (CYP2D6) x min(-1) (n=3) for CYP2D6*1 to catalyze dextromethaphan. The Km and Vmax are 111.36 +/- 10.89 micromol x L(-1) (n=3) and 222.2 +/- 20.12 pmol x nmol(-1) (CYP2D6) x min(-1) (n=3) for CYP2D6*10 to catalyze dextromethorphan. There is significant difference between CYP2D6*1 and CYP2D6*10 for Vmax and Km (P < 0.01). The clearance ratio of CYP2D6*1 is 25.0 and the clearance ratio of CYP2D6*10 is 2.0. The expressed CYP2D6*1 and CYP2D6*10 are useful tools to screen the metabolism profile of many xenobiotics and endobiotics in vitro, which are benefit to understand individual metabolism difference.
Animals ; Baculoviridae ; enzymology ; genetics ; Catalysis ; Cells, Cultured ; Chromatography, High Pressure Liquid ; methods ; Cytochrome P-450 CYP2D6 ; genetics ; metabolism ; Dextromethorphan ; metabolism ; Isoenzymes ; metabolism ; NADPH-Ferrihemoprotein Reductase ; genetics ; metabolism ; Plasmids ; Recombinant Proteins ; genetics ; metabolism ; Spectrometry, Mass, Electrospray Ionization ; Spodoptera ; cytology ; virology ; Transfection

The objective of this study was to investigate the correlation between the gene polymorphisms of drug metabolizing enzymes and the outcome of the first induction chemotherapy in patients with de novo acute myeloid leukemia (AML). 113 de novo AML patients were enrolled in this study. The genotypes of 11 single nucleotide polymorphisms (SNP) in drug metabolizing enzymes were detected by the SNPstream(®) Genotyping System. The correlation between the distribution of genotypes and the complete remission rate of first induction chemotherapy was analyzed by logical regression. The results showed that patients with variant genotype of CYP2D6 (rs16947) had a lower complete remission (CR) rate, as compared to those with wild type (p = 0.033, OR = 0.32, 95%CI 0.112 - 0.915); meanwhile the patients with variant genotype of GSTO2 (rs156697) had a higher CR rate as compared to those with wild type (p = 0.011, OR = 3.023, 95%CI 1.289 - 7.089). Combined analysis of the above polymorphisms, showed that patients with variant genotype of CYP2D6 and wild genotype of GSTO2 (V + W) had lower CR rates in comparison to patients with wild genotypes of both polymorphisms (p = 0.017, OR = 0.183, 95%CI 0.045 - 0.735). It is concluded that CYP2D6 (rs16947) and GSTO2 (rs156697) polymorphisms are independent factors influencing CR rates of the first induction chemotherapy in de novo AML patients.
Adolescent ; Adult ; Aged ; Antineoplastic Agents ; therapeutic use ; Child ; Cytochrome P-450 CYP2D6 ; genetics ; Female ; Genotype ; Glutathione Transferase ; genetics ; Humans ; Leukemia, Myeloid, Acute ; drug therapy ; enzymology ; genetics ; Male ; Middle Aged ; Polymorphism, Single Nucleotide ; Remission Induction ; Treatment Outcome ; Young Adult