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Marasanapalle VP, Masimirembwa C, Sivasubramanian R, Sayyed S, Weinzierl-Hinum A, Mehta D, Kapungu NN, Kanji C, Thelingwani R, Zack J. Investigation of the Differences in the Pharmacokinetics of CYP2D6 Substrates, Desipramine, and Dextromethorphan in Healthy African Subjects Carrying the Allelic Variants CYP2D6*17 and CYP2D6*29, When Compared with Normal Metabolizers. J Clin Pharmacol 2024; 64:578-589. [PMID: 37803948 DOI: 10.1002/jcph.2366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 10/04/2023] [Indexed: 10/08/2023]
Abstract
This study investigated the differences in the pharmacokinetics (PK) of dextromethorphan and desipramine in healthy African volunteers to understand the effect of allelic variants of the human cytochrome P450 2D6 (CYP2D6) enzyme, namely the diplotypes of CYP2D6*1/*2 (*1*1, *1*2, *2*2) and the genotypes of CYP2D6*17*17 and CYP2D6*29*29. Overall, 28 adults were included and split into 3 cohorts after genotype screening: CYP2D6*1/*2 (n = 12), CYP2D6*17*17 (n = 12), and CYP2D6*29*29 (n = 4). Each subject received a single oral dose of dextromethorphan 30 mg syrup on day 1 and desipramine 50 mg tablet on day 8. The PK parameters of area under the plasma concentration-time curve from time of dosing to time of last quantifiable concentration (AUClast), and extrapolated to infinity (AUCinf), and the maximum plasma concentration (Cmax) were determined. For both dextromethorphan and desipramine, AUCinf and Cmax were higher in subjects of the CYP2D6*29*29 and CYP2D6*17*17 cohorts, as compared with subjects in the CYP2D6*1/*2 diplotype cohort and with normal metabolizers from the literature. All PK parameters, including AUCinf, Cmax, and the elimination half-life, followed a similar trend: CYP2D6*17*17 > CYP2D6*29*29 > CYP2D6*1/*2. The plasma and urinary drug/metabolite exposure ratios of both drugs were higher in subjects of the CYP2D6*17*17 and CYP2D6*29*29 cohorts, when compared with subjects in the CYP2D6*1/*2 diplotype cohort. All adverse events were mild, except in 1 subject with CYP2D6*17*17 who had moderately severe headache with desipramine. These results indicate that subjects with CYP2D6*17*17 and CYP2D6*29*29 genotypes were 5-10 times slower metabolizers than those with CYP2D6*1/*2 diplotypes. These findings suggest that dose optimization may be required when administering CYP2D6 substrate drugs in African patients. Larger studies can further validate these findings.
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Affiliation(s)
| | - Collen Masimirembwa
- African Institute of Biomedical Science & Technology (AiBST), Harare, Zimbabwe
| | | | | | | | - Dheeraj Mehta
- Novartis Healthcare Private Limited, Hyderabad, India
| | | | - Comfort Kanji
- African Institute of Biomedical Science & Technology (AiBST), Harare, Zimbabwe
| | - Roslyn Thelingwani
- African Institute of Biomedical Science & Technology (AiBST), Harare, Zimbabwe
| | - Julia Zack
- Novartis Pharmaceutical Corporation, East Hanover, NJ, USA
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2
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El Akil S, Elouilamine E, Ighid N, Izaabel EH. Explore the distribution of (rs35742686, rs3892097 and rs1065852) genetic polymorphisms of cytochrome P4502D6 gene in the Moroccan population. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2022. [DOI: 10.1186/s43042-022-00369-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Abstract
Background
The CYP2D6 gene encodes a crucial enzyme involved in the metabolic pathways of many commonly used drugs. It is a highly polymorphic gene inducing an interethnic and interindividual variability in disease susceptibility and treatment response. The aim of this study is to evaluate the frequency of the three CYP2D6 most investigated alleles (CYP2D6*3, CYP2D6*4, and CYP2D6*10 alleles) in Morocco compared to other populations.
This study enrolled 321 healthy Moroccan subjects. CYP2D6 genotypes and allele frequencies were assessed using a restriction fragment length polymorphism–polymerase chain reaction genotyping method. The Principal Component Analysis (PCA) and dendrogram were conducted to evaluate genetic proximity between Moroccans and other populations depending on CYP2D6 allele frequencies.
Results
According to the current study, the results observed the homozygous wild type of the three studied SNPs were predominant among the Moroccan population, while 1.4% of Moroccans carried the CYP2D6*4 allele responsible for a Poor Metabolizer phenotype and associated with low enzyme activity which may induce a treatment failure. The PCA and cluster dendrogram tools revealed genetic proximity between Moroccans and Mediterranean, European and African populations, versus a distancing from Asian populations.
Conclusion
The distribution of CYP2D6 polymorphisms within Morocco follows the patterns generally found among the Mediterranean, European and African populations. Furthermore, these results will help to lay a basis for clinical studies, aimed to introduce and optimize a personalized therapy in the Moroccan population.
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3
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Tan EY, Bharwani L, Chia YH, Soong RCT, Lee SSY, Chen JJC, Chan PMY. Impact of cytochrome P450 2D6 polymorphisms on decision-making and clinical outcomes in adjuvant hormonal therapy for breast cancer. World J Clin Oncol 2022; 13:712-724. [PMID: 36160461 PMCID: PMC9476606 DOI: 10.5306/wjco.v13.i8.712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 08/08/2021] [Accepted: 07/18/2022] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND There are concerns that tamoxifen is less effective in Asian women because of the high prevalence of impaired function cytochrome P450 2D6 (CYP2D6) polymor-phisms.
AIM To evaluate how knowledge of CYP2D6 genotype impacted the choice of hormonal agent and how CYP2D6 genotype and agent were associated with clinical outcomes.
METHODS Eighty-two women were recruited. Seventy-eight completed CYP2D6 genotyping and were categorized into poor, intermediate (IM) and extensive or ultra metabolizer phenotypes. Women with poor metabolizer and IM phenotypes were recommended aromatase inhibitors as the preferred agent.
RESULTS More than 70% of the women had an IM phenotype, 32% an extensive or ultra metabolizer phenotype, and 0% had a poor metabolizer phenotype. Regardless of genotype, more women opted for aromatase inhibitors. Overall, 80% of women completed 5 years of hormonal therapy. Five women developed recurrence, 3 contralateral breast cancer, 5 died, and 1 was diagnosed with a second primary cancer. Five-year recurrence-free and overall survival were slightly better in women with the extensive or ultra metabolizer phenotype compared to those with the IM phenotype, though not statistically significant [P = 0.743, hazard ratio (HR): 1.441, 95% confidence interval (CI): 0.191 to 10.17 and P = 0.798, HR: 1.327, 95%CI: 0.172 to 9.915, respectively]. Women receiving aromatase inhibitors also appeared to have a better, but also nonsignificant, 5-year recurrence-free and overall survival (P = 0.253, HR: 0.368, 95%CI: 0.031 to 0.258 and P = 0.292, HR: 0.252, 95%CI: 0.005 to 4.951, respectively).
CONCLUSION The IM phenotype was highly prevalent but was not associated with clinical outcome.
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Affiliation(s)
- Ern-Yu Tan
- Department of General Surgery, Tan Tock Seng Hospital, Singapore 308433, Singapore
- Lee Kong Chian School of Medicine, Singapore 308232, Singapore
- Institute of Molecular and Cell Biology, A*STAR, Singapore 138673, Singapore
| | - Lavina Bharwani
- Department of Medical Oncology, Tan Tock Seng Hospital, Singapore 308433, Singapore
| | - Yee-Hong Chia
- Department of Medical Oncology, Tan Tock Seng Hospital, Singapore 308433, Singapore
| | - Richie C T Soong
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 119077, Singapore
| | - Sherylyn S Y Lee
- Department of General Surgery, Tan Tock Seng Hospital, Singapore 308433, Singapore
| | - Juliana J C Chen
- Department of General Surgery, Tan Tock Seng Hospital, Singapore 308433, Singapore
| | - Patrick M Y Chan
- Department of General Surgery, Tan Tock Seng Hospital, Singapore 308433, Singapore
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Ono K, Iwasaki YK, Akao M, Ikeda T, Ishii K, Inden Y, Kusano K, Kobayashi Y, Koretsune Y, Sasano T, Sumitomo N, Takahashi N, Niwano S, Hagiwara N, Hisatome I, Furukawa T, Honjo H, Maruyama T, Murakawa Y, Yasaka M, Watanabe E, Aiba T, Amino M, Itoh H, Ogawa H, Okumura Y, Aoki-Kamiya C, Kishihara J, Kodani E, Komatsu T, Sakamoto Y, Satomi K, Shiga T, Shinohara T, Suzuki A, Suzuki S, Sekiguchi Y, Nagase S, Hayami N, Harada M, Fujino T, Makiyama T, Maruyama M, Miake J, Muraji S, Murata H, Morita N, Yokoshiki H, Yoshioka K, Yodogawa K, Inoue H, Okumura K, Kimura T, Tsutsui H, Shimizu W. JCS/JHRS 2020 Guideline on Pharmacotherapy of Cardiac Arrhythmias. Circ J 2022; 86:1790-1924. [DOI: 10.1253/circj.cj-20-1212] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
| | - Yu-ki Iwasaki
- Department of Cardiovascular Medicine, Nippon Medical School
| | - Masaharu Akao
- Department of Cardiovascular Medicine, National Hospital Organization Kyoto Medical Center
| | - Takanori Ikeda
- Department of Cardiovascular Medicine, Toho University Graduate School of Medicine
| | - Kuniaki Ishii
- Department of Pharmacology, Yamagata University Faculty of Medicine
| | - Yasuya Inden
- Department of Cardiology, Nagoya University Graduate School of Medicine
| | - Kengo Kusano
- Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center
| | - Yoshinori Kobayashi
- Division of Cardiology, Department of Medicine, Tokai University Hachioji Hospital
| | | | - Tetsuo Sasano
- Department of Cardiovascular Medicine, Tokyo Medical and Dental University
| | - Naokata Sumitomo
- Department of Pediatric Cardiology, Saitama Medical University International Medical Center
| | - Naohiko Takahashi
- Department of Cardiology and Clinical Examination, Faculty of Medicine, Oita University
| | - Shinichi Niwano
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | | | | | - Tetsushi Furukawa
- Department of Bio-information Pharmacology, Medical Research Institute, Tokyo Medical and Dental University
| | - Haruo Honjo
- Research Institute of Environmental Medicine, Nagoya University
| | - Toru Maruyama
- Department of Hematology, Oncology and Cardiovascular Medicine, Kyushu University Hospital
| | - Yuji Murakawa
- The 4th Department of Internal Medicine, Teikyo University School of Medicine, Mizonokuchi Hospital
| | - Masahiro Yasaka
- Department of Cerebrovascular Medicine and Neurology, Clinical Research Institute, National Hospital Organization Kyushu Medical Center
| | - Eiichi Watanabe
- Department of Cardiology, Fujita Health University School of Medicine
| | - Takeshi Aiba
- Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center
| | - Mari Amino
- Department of Cardiovascular Medicine, Tokai University School of Medicine
| | - Hideki Itoh
- Division of Patient Safety, Hiroshima University Hospital
| | - Hisashi Ogawa
- Department of Cardiology, National Hospital Organisation Kyoto Medical Center
| | - Yasuo Okumura
- Division of Cardiology, Department of Medicine, Nihon University School of Medicine
| | - Chizuko Aoki-Kamiya
- Department of Obstetrics and Gynecology, National Cerebral and Cardiovascular Center
| | - Jun Kishihara
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Eitaro Kodani
- Department of Cardiovascular Medicine, Nippon Medical School Tama Nagayama Hospital
| | - Takashi Komatsu
- Division of Cardiology, Department of Internal Medicine, Iwate Medical University School of Medicine
| | | | | | - Tsuyoshi Shiga
- Department of Clinical Pharmacology and Therapeutics, The Jikei University School of Medicine
| | - Tetsuji Shinohara
- Department of Cardiology and Clinical Examination, Faculty of Medicine, Oita University
| | - Atsushi Suzuki
- Department of Cardiology, Tokyo Women's Medical University
| | - Shinya Suzuki
- Department of Cardiovascular Medicine, The Cardiovascular Institute
| | - Yukio Sekiguchi
- Department of Cardiology, National Hospital Organization Kasumigaura Medical Center
| | - Satoshi Nagase
- Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center
| | - Noriyuki Hayami
- Department of Fourth Internal Medicine, Teikyo University Mizonokuchi Hospital
| | | | - Tadashi Fujino
- Department of Cardiovascular Medicine, Toho University, Faculty of Medicine
| | - Takeru Makiyama
- Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University
| | - Mitsunori Maruyama
- Department of Cardiovascular Medicine, Nippon Medical School Musashi Kosugi Hospital
| | - Junichiro Miake
- Department of Pharmacology, Tottori University Faculty of Medicine
| | - Shota Muraji
- Department of Pediatric Cardiology, Saitama Medical University International Medical Center
| | | | - Norishige Morita
- Division of Cardiology, Department of Medicine, Tokai University Hachioji Hospital
| | - Hisashi Yokoshiki
- Department of Cardiovascular Medicine, Sapporo City General Hospital
| | - Koichiro Yoshioka
- Division of Cardiology, Department of Internal Medicine, Tokai University School of Medicine
| | - Kenji Yodogawa
- Department of Cardiovascular Medicine, Nippon Medical School
| | | | - Ken Okumura
- Division of Cardiology, Saiseikai Kumamoto Hospital Cardiovascular Center
| | - Takeshi Kimura
- Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University
| | - Hiroyuki Tsutsui
- Department of Cardiovascular Medicine, Faculty of Medical Sciences, Kyushu University
| | - Wataru Shimizu
- Department of Cardiovascular Medicine, Nippon Medical School
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5
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Okubo Y, Ohtsuki M, Komine M, Imafuku S, Kassir N, Petric R, Nemoto O. Population pharmacokinetic and exposure-response analysis of apremilast in Japanese subjects with moderate to severe psoriasis. J Dermatol 2021; 48:1652-1664. [PMID: 34396569 PMCID: PMC9290614 DOI: 10.1111/1346-8138.16068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 07/02/2021] [Indexed: 01/08/2023]
Abstract
Apremilast is an orally available phosphodiesterase 4 inhibitor used for the treatment of moderate to severe psoriasis. The aims of this analysis were to develop a population pharmacokinetic (PPK) model of apremilast based on observed data from phase 1 studies combined with clinical trial data from subjects with moderate to severe psoriasis, and to develop exposure–response (E‐R) models to determine whether Japanese subjects with moderate to severe psoriasis achieve response to apremilast treatment similar to that observed in non‐Japanese, predominantly Caucasian subjects with moderate to severe psoriasis. The PPK model demonstrated that apremilast plasma concentrations and overall apparent clearance rate were comparable between the Japanese and Caucasian subgroups. The E‐R analyses of ≥75% or ≥50% improvement from baseline in Psoriasis Area and Severity Index score and achievement of static Physician Global Assessment score of 0 (clear) or 1 (almost clear) at week 16 indicated that apremilast treatment in Japanese subjects approached the maximal effect with response rates comparable to those in predominantly Caucasian subjects. Overall, the analyses confirm that the approved apremilast 30 mg b.i.d. dose is appropriate for Japanese subjects with moderate to severe psoriasis, with an efficacy profile similar to that previously observed in Caucasian subjects.
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Affiliation(s)
| | | | | | | | - Nastya Kassir
- Certara Strategic Consulting, Princeton, New Jersey, USA
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6
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Sugimoto A, Suzuki Y, Orime N, Hayashi T, Yoshinaga K, Egawa J, Ono S, Sugai T, Inoue Y, Someya T. The lowest effective plasma concentration of atomoxetine in pediatric patients with attention deficit/hyperactivity disorder: A non-randomized prospective interventional study. Medicine (Baltimore) 2021; 100:e26552. [PMID: 34232195 PMCID: PMC8270591 DOI: 10.1097/md.0000000000026552] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 05/28/2021] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Atomoxetine (ATX) is used as a first-line, non-stimulant treatment for attention-deficit/hyperactivity disorder (ADHD), although no studies have systematically examined the relationship between plasma concentration and clinical efficacy. We conducted this non-randomized prospective interventional study to examine the relationship between plasma concentration of ATX and clinical efficacy. METHODS Forty-three ADHD pediatric patients received ATX, and the steady-state through plasma concentration of the last daily dose that was maintained for at least 4 weeks were determined by high-performance liquid chromatography. RESULTS The receiver operating characteristic curve suggested that when plasma concentration exceeded 64.60 ng/mL, scores on the ADHD-Rating Scale improved by 50% or more (P = .14). Although 6 of the 8 final responders were unresponsive at the initial dose (.72 ± .04 mg/kg [mean ± standard deviation]), they responded after increasing the ATX dose to the final dose (1.52 ± .31 mg/kg). Excluding 7 outlier participants, the concentration was 83.3 ± 32.3 ng/mL in 7 responders and was significantly higher than 29.5 ± 23.9 ng/mL (P < .01) for the 29 non-responders. CONCLUSIONS These results suggest that a minimum effective plasma concentration of ATX is required to achieve sufficient clinical efficacy. We hypothesized a mechanism that results in the realization of a clinical effect when the plasma concentration exceeds a certain threshold in the potential response group, whereas will not improve even if the plasma concentration is increased in the unqualified non-responder group.
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Affiliation(s)
- Atsunori Sugimoto
- Department of Community Psychiatric Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
- Department of Psychiatry, Niigata Psychiatric Center, Nagaoka, Japan
| | - Yutaro Suzuki
- Department of Psychiatry, Niigata University Medical and Dental Hospital, Niigata, Japan
- Department of Psychiatry, Suehirobashi Hospital Keiaikai, Niigata, Japan
| | - Naoki Orime
- Department of Psychiatry, Niigata University Medical and Dental Hospital, Niigata, Japan
| | - Taketsugu Hayashi
- Department of Psychiatry, Niigata Psychiatric Center, Nagaoka, Japan
| | - Kiyohiro Yoshinaga
- Department of Psychiatry, Niigata Psychiatric Center, Nagaoka, Japan
- Department of Psychiatry, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Jun Egawa
- Department of Psychiatry, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Shin Ono
- Department of Community Psychiatric Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
- Department of Psychiatry, Niigata Psychiatric Center, Nagaoka, Japan
| | - Takuro Sugai
- Comprehensive Medical Education Center, Niigata University School of Medicine, Niigata, Japan
| | - Yoshimasa Inoue
- Department of Psychiatry, Dokkyo Medical University, Soka, Japan
| | - Toshiyuki Someya
- Department of Psychiatry, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
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Molden E, Jukić MM. CYP2D6 Reduced Function Variants and Genotype/Phenotype Translations of CYP2D6 Intermediate Metabolizers: Implications for Personalized Drug Dosing in Psychiatry. Front Pharmacol 2021; 12:650750. [PMID: 33967790 PMCID: PMC8100508 DOI: 10.3389/fphar.2021.650750] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 03/23/2021] [Indexed: 12/14/2022] Open
Abstract
Genetic differences in cytochrome P450 (CYP)-mediated metabolism have been known for several decades. The clinically most important polymorphic CYP enzyme is CYP2D6, which plays a key role in the metabolism of many antidepressants and antipsychotics, along with a range of non-psychiatric medications. Dose individualization based on CYP2D6 genotype to improve the effect and safety of drug treatment has been an ambition for a long time. Clinical use of CYP2D6 genotyping is steadily increasing; however, for pre-emptive genotyping to be successful in predicting individual dose requirements, high precision of genotype-to-phenotype translations are required. Recently, guidelines for assigning CYP2D6 enzyme activity scores of CYP2D6 variant alleles, and subsequent diplotype-to-phenotype translations, were published by the Clinical Pharmacogenetics Implementation Consortium (CPIC) and the Dutch Pharmacogenetics Working Group. Consensus on assigning activity scores of CYP2D6 variant alleles and translating diplotype scores into CYP2D6 poor, intermediate, normal, or ultrarapid metabolizer groups were obtained by consulting 37 international experts. While assigning enzyme activities of non-functional (score 0) and fully functional (score 1) alleles are straightforward, reduced function variant alleles are more complex. In this article, we present data showing that the assigned activity scores of reduced function variant alleles in current guidelines are not of sufficient precision; especially not for CYP2D6*41, where the guideline activity score is 0.5 compared to 0.05–0.15 in pharmacogenetic studies. Due to these discrepancies, CYP2D6 genotypes with similar guidelinediplotype scores exhibit substantial differences in CYP2D6 metabolizer phenotypes. Thus, it is important that the guidelines are updated to be valid in predicting individual dose requirements of psychiatric drugs and others metabolized by CYP2D6.
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Affiliation(s)
- Espen Molden
- Center for Psychopharmacology, Diakonhjemmet Hospital, Oslo, Norway.,Section for Pharmacology and Pharmaceutical Biosciences, Departement of Pharmacy, University of Oslo, Oslo, Norway
| | - Marin M Jukić
- Section of Pharmacogenetics, Department of Physiology and Pharmacology, Biomedicum 5B, Karolinska Institutet, Stockholm, Sweden.,Department of Physiology, Faculty of Pharmacy, University of Belgrade, Belgrade, Serbia
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8
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Wang T, Zhou Y, Cao G. Pharmacogenetics of tamoxifen therapy in Asian populations: from genetic polymorphism to clinical outcomes. Eur J Clin Pharmacol 2021; 77:1095-1111. [PMID: 33515076 DOI: 10.1007/s00228-021-03088-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 01/11/2021] [Indexed: 12/15/2022]
Abstract
BACKGROUND Compared with western countries, Asian breast cancer patients have unique pathological and biological characteristics. Most of them are premenopausal women with HR positive. Tamoxifen as the first-line drug for premenopausal women with HR+ is involved in multiple enzymes and transporters during metabolizing and transporting process. Variants that cause decreased or inactive gene products leading to abnormal responses in tamoxifen therapy have well been studied in western countries, whereas such information is much less reported in Asian populations. OBJECTIVE In order to elucidate the relationship between genetic variants and tamoxifen-induced individual drug reactions in different Asian populations and further identify genotypes/phenotypes with potential therapeutic significance. METHODS We reviewed the frequencies of genetic variants in major enzymes and transporter genes involved in the metabolism and transport of tamoxifen across Asian populations as well as significant correlations between genotypes/metabolic phenotypes and metabolites concentrations or BC clinical outcomes. RESULTS Significant inter-ethnic differences in allele frequencies was found among Asian populations, such as CYP2D6*4, *10, *41, CYP2C9*2, ABCB1 C3435T and SLCO1B1*5, and CYP2D6*10/*10 is the most common genotype correlated with adverse clinical outcomes. Moreover, we summarized the barriers and controversies of implementing pharmacogenetics in tamoxifen therapy and concluded that more population-specific pharmacogenetic studies are needed in the future. CONCLUSION This review revealed more systematic pharmacogenomics of genes involved in the metabolism and transport besides CYP2D6, are required to optimize the genotyping strategies and guide the personalized tamoxifen therapy in Asian populations.
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Affiliation(s)
- Tingyu Wang
- College of Pharmacy, Hubei University of Chinese Medicine, Wuhan, 430065, China
| | - Yitian Zhou
- Department of Physiology and Pharmacology, Karolinska Institutet, 17177, Stockholm, Sweden
| | - Guosheng Cao
- College of Pharmacy, Hubei University of Chinese Medicine, Wuhan, 430065, China.
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9
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Kisoi M, Imai M, Yamamura M, Sakaguchi Y, Murata S, Ichikawa A, Kinoshita K. Unique Genotyping Protocol of CYP2D6 Allele Frequency Using Real Time Quantitative PCR from Japanese Healthy Women. Biol Pharm Bull 2020; 43:904-907. [PMID: 32378566 DOI: 10.1248/bpb.b19-00512] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
CYP2D6 is an important drug-metabolizing enzyme involved in the metabolism of 20-25% of commonly prescribed drugs. Genetic polymorphism of CYP has clinically significant modifications in patients' drug-metabolizing capacities. Since gene copy number variation (CNV) and single nucleotide polymorphism (SNP) frequently occur in the CYP2D6 gene, which the activity of CYP2D6 particularly depend on the genetic factors. This study aimed to investigate the frequencies of CYP2D6 genotypes in a Japanese female subject of 216 healthy volunteers. The volunteers were genotyped for CNV Exon 9 and four CYP2D6 genetic variants (*2, *5, *10, *14, *41) performed by TaqMan® genotyping assays. The CNV allele frequencies were 82.9% for two copies, 11.6% for one copy, 4.6% for three copies and 0.9% for zero copy, respectively. The frequencies of CYP2D6*1, *2, *5, *10, *14, and *41 were 38.7, 16.7, 6.3, 34.7, 0.2, and 1.2%, respectively. CYP2D6*5 and *14 were the major defective alleles. However, this genotyping is labor intensive, time consuming, and costly. We report an optimized novel protocol for the determination of CNV and SNP in CYP2D6 gene by real-time quantitative PCR. This can lower the cost and accurately determine CNV and SNP in the CYP2D6 gene with a higher output and enabling reliable estimates of disease prediction in large epidemiological samples.
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Affiliation(s)
- Madoka Kisoi
- School of Pharmaceutical Sciences, Mukogawa Women's University
| | - Miho Imai
- School of Pharmaceutical Sciences, Mukogawa Women's University
| | - Miwako Yamamura
- School of Pharmaceutical Sciences, Mukogawa Women's University
| | - Yui Sakaguchi
- School of Pharmaceutical Sciences, Mukogawa Women's University
| | - Shigenori Murata
- School of Pharmaceutical Sciences, Mukogawa Women's University.,Institute of Biosciences, Mukogawa Women's University
| | - Atsushi Ichikawa
- Institute of Biosciences, Mukogawa Women's University.,Bio Education Laboratory
| | - Kenji Kinoshita
- School of Pharmaceutical Sciences, Mukogawa Women's University.,Institute of Biosciences, Mukogawa Women's University.,Bio Education Laboratory
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10
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Won DY, Byun SJ, Jeong JS, Shin JY. Association Between Acetylcholinesterase Inhibitors and Osteoporotic Fractures in Older Persons With Alzheimer's Disease. J Am Med Dir Assoc 2020; 21:1128-1133.e1. [PMID: 31926798 DOI: 10.1016/j.jamda.2019.12.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 12/02/2019] [Accepted: 12/03/2019] [Indexed: 01/19/2023]
Abstract
OBJECTIVE To identify the association between the use of acetylcholinesterase inhibitors (AChEIs) and risk of osteoporotic fractures in older persons with Alzheimer's disease (AD). DESIGN, SETTING, AND PARTICIPANTS A nested case-control study was conducted using the Korean National Health Insurance Service-National Elderly Cohort database. Patients with AD who were newly diagnosed with osteoporotic fractures were identified as cases. Up to 3 controls were matched with cases according to age, sex, and duration of follow-up. METHODS Participants were considered as exposed to AChEIs if they had been prescribed at least 1 AChEI during a period of 2 years before the index date. A conditional logistic regression was performed to estimate the adjusted odds ratios with 95% confidence intervals for the association between the use of AChEIs and osteoporotic fractures in patients with AD. We also examined the impact of dose, duration of treatment, and timing of exposure on the estimates of the association between the use of AChEIs and risk of osteoporotic fractures. RESULTS The study cohort comprised 45,006 patients diagnosed with AD, of which 9470 patients, including 2385 cases and 7085 controls, were available for the study. The mean ages (standard deviations) were 78.6 (6.9) years in the cases and 80.0 (6.9) years in the controls. Adjusted odds ratios for the association between the use of AChEIs and osteoporotic fractures in patients with AD was 1.18 (95% confidence interval 1.07-1.31). CONCLUSIONS AND IMPLICATIONS Our data indicated that the use of AChEIs was not associated with a reduced risk of osteoporotic fractures in patients with AD; in contrast, their use was associated with a mild increased risk of osteoporotic fractures. Thus, clinicians should consider the possibility of AChEIs-associated fractures among older persons with AD. Findings of this study will support shared decision making among prescribers, patients, and caregivers.
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Affiliation(s)
- Dae Yeon Won
- School of Pharmacy, Sungkyunkwan University, Suwon, Gyeong gi-do, South Korea
| | - Seong Jun Byun
- School of Pharmacy, Sungkyunkwan University, Suwon, Gyeong gi-do, South Korea
| | - Jin Sook Jeong
- School of Pharmacy, Sungkyunkwan University, Suwon, Gyeong gi-do, South Korea
| | - Ju-Young Shin
- School of Pharmacy, Sungkyunkwan University, Suwon, Gyeong gi-do, South Korea.
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Puaprasert K, Chu C, Saralamba N, Day NPJ, Nosten F, White NJ, Dondorp AM, Imwong M. Real time PCR detection of common CYP2D6 genetic variants and its application in a Karen population study. Malar J 2018; 17:427. [PMID: 30442143 PMCID: PMC6238304 DOI: 10.1186/s12936-018-2579-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 11/09/2018] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Plasmodium vivax malaria is characterized by relapses arising from the hypnozoite stages in the liver. The only currently registered drug for radical treatment to prevent relapse is primaquine. Primaquine, a prodrug, requires metabolism through the liver cytochrome CYP2D6 isoenzyme to its active metabolite. Mutations in the CYP2D6 gene may thus affect primaquine efficacy. A SNPs genotyping technique was developed to characterize the CYP2D6 genetic variants and tested this in the patients with Plasmodium vivax infection collected in a Karen population on the Thailand-Myanmar border, where P. vivax malaria is endemic. METHODS Direct sequencing of PCR-reamplified products (DSP) was used to uncover exonic CYP2D6 sequence variations. Subsequently, an allele-specific oligonucleotide probe real-time SNPs genotyping (ASO) assay was developed for rapid detection of the four clinically relevant CYP2D6 variants occurring in this population. These two in-house developed assays were used to genotype CYP2D6 mutations in blood samples obtained from 70 Karen adults. RESULTS Results showed a high degree of concordance between the DSP and ASO methods. Six CYP2D6 point mutations were identified within the Karen population: C100T, C1039T, G1661C, G1846A, C2850T and G4180C, at frequencies of 0.43, 0.43, 0.76, 0.02, 0.32 and 0.76, respectively. The CYP2D6*2, *4, *5, *10 and *36 allelic frequencies were 0.33, 0.02, 0.03, 0.40 and 0.01, respectively. Alleles conferring an intermediate CYP2D6 metabolizer phenotype comprised 46% of the total number of alleles. CONCLUSION The newly developed ASO assay is a reliable and rapid tool for large-scale CYP2D6 genotyping. The high frequency of the CYP2D6*10 allele in the Karen population warrants further assessment of its association with the radical curative efficacy of primaquine.
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Affiliation(s)
- Kanokpich Puaprasert
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Cindy Chu
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Naowarat Saralamba
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas P J Day
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Francois Nosten
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Nicholas J White
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Arjen M Dondorp
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Mallika Imwong
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
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Byeon JY, Kim YH, Lee CM, Kim SH, Chae WK, Jung EH, Choi CI, Jang CG, Lee SY, Bae JW, Lee YJ. CYP2D6 allele frequencies in Korean population, comparison with East Asian, Caucasian and African populations, and the comparison of metabolic activity of CYP2D6 genotypes. Arch Pharm Res 2018; 41:921-930. [PMID: 30191460 DOI: 10.1007/s12272-018-1075-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 08/30/2018] [Indexed: 01/09/2023]
Abstract
Cytochrome P450 (CYP) 2D6 is present in less than about 2% of all CYP enzymes in the liver, but it is involved in the metabolism of about 25% of currently used drugs. CYP2D6 is the most polymorphic among the CYP enzymes. We determined alleles and genotypes of CYP2D6 in 3417 Koreans, compared the frequencies of CYP2D6 alleles with other populations, and observed the differences in pharmacokinetics of metoprolol, a prototype CYP2D6 substrate, depending on CYP2D6 genotype. A total of 3417 unrelated healthy subjects were recruited for the genotyping of CYP2D6 gene. Among them, 42 subjects with different CYP2D6 genotypes were enrolled in the pharmacokinetic study of metoprolol. The functional allele *1 and *2 were present in frequencies of 34.6 and 11.8%, respectively. In decreased functional alleles, *10 was the most frequent with 46.2% and *41 allele was present in 1.4%. The nonfunctional alleles *5 and *14 were present at 4.5 and 0.5% frequency, respectively. The *X × N allele was present at a frequency of 1.0%. CYP2D6*1/*1, *1/*2 and *2/*2 genotypes with normal enzyme activity were present in 12.1%, 8.6% and 1.4% of the subjects, respectively. CYP2D6*5/*5, *5/*14, and *14/*14 genotypes classified as poor metabolizer were only present in 4, 2, and 1 subjects, respectively. Mutant genotypes with frequencies of more than 1% were CYP2D6*1/*10 (32.0%), *10/*10 (22.3%), *2/*10 (11.7%), *5/*10 (3.7%), *1/*5 (2.5%), and *10/*41 (1.2%). The relative clearance of metoprolol in CYP2D6*1/*10, *1/*5, *10/*10, *5/*10, and *5/*5 genotypes were 69%, 57%, 24%, 14% and 9% of CYP2D6*wt/*wt genotype, respectively. These results will be very useful in establishing a strategy for precision medicine related to the genetic polymorphism of CYP2D6.
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Affiliation(s)
- Ji-Young Byeon
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Young-Hoon Kim
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Choong-Min Lee
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Se-Hyung Kim
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Won-Ki Chae
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Eui-Hyun Jung
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Chang-Ik Choi
- College of Pharmacy, Dongguk University-Seoul, Goyang, 10326, Republic of Korea
| | - Choon-Gon Jang
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Seok-Yong Lee
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
| | - Jung-Woo Bae
- College of Pharmacy, Keimyung University, Daegu, 42601, Republic of Korea.
| | - Yun Jeong Lee
- College of Pharmacy, Dankook University, Cheonan, 31116, Republic of Korea.
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Kagami S, Kaneko M, Kishi A, Katori T. Prolonged growth of infantile hemangioma after pulsed dye laser and oral propranolol treatment. J Dermatol 2018; 45:1109-1112. [PMID: 29952019 DOI: 10.1111/1346-8138.14517] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 05/21/2018] [Indexed: 12/15/2022]
Abstract
Infantile hemangiomas are the most common tumor of childhood and undergo rapid growth during early infancy followed by gradual involution. After involution, residual lesions sometimes remain. Oral propranolol usually induces earlier involution and redness reduction of infantile hemangiomas. However, the optimal treatment duration is unknown and infantile hemangiomas sometimes recur after cessation of treatment. We report three Japanese patients with recurrent infantile hemangiomas on their cheek. These patients were a 1-month-old female baby with a superficial infantile hemangioma, a 3-month-old female baby with a mixed infantile hemangioma and a 4-month-old male baby with a mixed infantile hemangioma. Two of them also received pulsed dye laser treatment. They did not reach complete or nearly complete resolution of infantile hemangiomas at week 25. These patients experienced regrowth of their infantile hemangioma after 20 months of age and took propranolol after the age of 24 months. There were no severe adverse effects. Propranolol may not only be therapeutic but also prophylactic. Patients with infantile hemangiomas who have taken oral propranolol should be followed up at least 6 months after cessation of treatment, especially infantile hemangiomas on the cheek, and those with partial response to propranolol may require close attention in prolonged growth.
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Affiliation(s)
- Shinji Kagami
- Department of Dermatology, Kanto Central Hospital, Tokyo, Japan
| | - Masahide Kaneko
- Department of Pediatrics, Kanto Central Hospital, Tokyo, Japan
| | - Akiko Kishi
- Department of Dermatology, Toranomon Hospital, Tokyo, Japan
| | - Tatsuo Katori
- Department of Pediatrics, Showa General Hospital, Tokyo, Japan
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14
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Kagami S, Kaneko M, Katori T. Thirty-two Japanese cases of infantile hemangiomas treated with oral propranolol. J Dermatol 2018; 45:719-722. [DOI: 10.1111/1346-8138.14316] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 02/28/2018] [Indexed: 11/30/2022]
Affiliation(s)
- Shinji Kagami
- Department of Dermatology; Kanto Central Hospital; Tokyo Japan
| | - Masahide Kaneko
- Department of Pediatrics; Kanto Central Hospital; Tokyo Japan
| | - Tatsuo Katori
- Department of Pediatrics; Showa General Hospital; Tokyo Japan
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15
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Yokoyama S, Tamaru S, Tamaki S, Nakanishi D, Mori A, Yamakawa T, Ao T, Sakata Y, Mizuno T, Iwamoto T, Watanabe K, Simomura M, Kawakami K, Konishi N, Kageyama S, Ohtani S, Yamada T, Ban S, Ooi K. Genetic Risk Factors Associated With Antiemetic Efficacy of Palonosetron, Aprepitant, and Dexamethasone in Japanese Breast Cancer Patients Treated With Anthracycline-based Chemotherapy. Clin Breast Cancer 2017; 18:e157-e165. [PMID: 28735677 DOI: 10.1016/j.clbc.2017.05.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 04/23/2017] [Accepted: 05/22/2017] [Indexed: 10/19/2022]
Abstract
INTRODUCTION Breast cancer patients often receive anthracycline-based chemotherapy, and chemotherapy-induced nausea and vomiting (CINV) remains one of the most uncomfortable and distressing adverse reactions. Poor control of CINV reduces the relative dose intensity of chemotherapy agents, which has been associated with poor clinical outcomes and shorter survival. The aim of the present study was to identify genetic risk factors associated with anthracycline-based CINV. PATIENTS AND METHODS We evaluated CINV attributable to anthracycline-based chemotherapy in Japanese breast cancer patients treated with an antiemetic regimen that included palonosetron, aprepitant, and dexamethasone. Furthermore, we investigated the associations between CINV and single nucleotide polymorphisms in 6 candidate genes. RESULTS Emesis episodes were rarely observed in the 125 patients included in the present survey (7.2%; n = 9); however, significant nausea occurred in more than one half of the patients (52.8%; n = 66). In particular, acute significant nausea was not effectively controlled. Multivariate logistic regression analysis revealed that the ABCG2 (rs2231142) AA genotype is significantly associated with acute significant nausea (odds ratio, 4.87; 95% confidence interval, 1.01-23.60; P = .049). CONCLUSION The findings of the present study provide significant insights for developing personalized antiemetic strategies for breast cancer patients receiving anthracycline-based chemotherapy.
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Affiliation(s)
- Satoshi Yokoyama
- Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Suzuka, Japan.
| | - Satoshi Tamaru
- Clinical Research Support Center, Mie University Hospital Hematology and Oncology, Mie University Hospital, Tsu, Japan
| | - Shinya Tamaki
- Department of Pharmacy, Hokkaido Cancer Center, Sapporo, Japan
| | | | - Akiya Mori
- Department of Pharmacy, Suzuka General Hospital, Suzuka, Japan
| | - Tomokazu Yamakawa
- Department of Pharmacy, Mie Prefectural General Medical Center, Yokkaichi, Japan
| | - Takaaki Ao
- Division of Pharmacy, Suzuka Kaisei Hospital, Suzuka, Japan
| | - Yasuhiko Sakata
- Department of Pharmacy, Hiroshima City Hiroshima Citizens Hospital, Hiroshima, Japan
| | - Toshiro Mizuno
- Department of Hematology and Oncology, Mie University Graduate School of Medicine, Tsu, Japan
| | - Takuya Iwamoto
- Department of Pharmacy, Mie University Hospital, Tsu, Japan
| | - Kenichi Watanabe
- Department of Breast Surgery, Hokkaido Cancer Center, Sapporo, Japan
| | - Makoto Simomura
- Department of Surgery, Matsusaka City Hospital, Matsusaka, Japan
| | - Keiki Kawakami
- Division of Hematology/Oncology, Suzuka General Hospital, Suzuka, Japan
| | - Naomi Konishi
- Department of Surgery, Mie Prefectural General Medical Center, Yokkaichi, Japan
| | - Shinichi Kageyama
- Department of Immuno-Gene Therapy, Mie University Graduate School of Medicine, Tsu, Japan
| | - Shoichiro Ohtani
- Department of Breast Surgery, Hiroshima City Hiroshima Citizens Hospital, Hiroshima, Japan
| | - Tomomi Yamada
- Department of Medical Innovation, Osaka University Hospital, Suita, Japan
| | - Susumu Ban
- Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Suzuka, Japan
| | - Kazuya Ooi
- Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Suzuka, Japan
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Effect of 22 CYP2D6 variants found in the Chinese population on tolterodine metabolism in vitro. Chem Biol Interact 2017; 264:10-15. [PMID: 28087463 DOI: 10.1016/j.cbi.2017.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 12/15/2016] [Accepted: 01/09/2017] [Indexed: 11/22/2022]
Abstract
Cytochrome P450 2D6 (CYP2D6) is an important member of the cytochrome P450 enzyme superfamily. We recently identified 22 novel variants in the Chinese population using PCR and bidirectional sequencing methods. The aim of this study is to characterize the enzymatic activity of these variants and their effects on the metabolism of the antimuscarinic drug tolterodine in vitro. A baculovirus-mediated expression system was used to express wild-type CYP2D6 and 24 variants (CYP2D6*2, CYP2D6*10, and 22 novel CYP2D6 variants) at high levels. The insect microsomes expressing CYP2D6 proteins were incubated with 0.1-50 μM tolterodine at 37 °C for 30 min and the metabolites were analyzed by high-performance liquid chromatography-tandem mass spectrometry system. Of the 24 CYP2D6 variants tested, 2 variants (CYP2D6*92 and CYP2D6*96) were found to be catalytically inactive, 4 variants (CYP2D6*94, F164L, F219S and D336N) exhibited markedly increased intrinsic clearance values (Vmax/Km) compared with the wild-type (from 66.34 to 99.79%), whereas 4 variants (CYP2D6*10, *93, *95 and E215K) exhibited significantly decreased values (from 49.02 to 98.50%). This is the first report of all these rare alleles for tolterodine metabolism and these findings suggest that more attention should be paid to subjects carrying these infrequent CYP2D6 alleles when administering tolterodine in the clinic.
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Chen B, Huang JJ, Chen HF, Xu BM. Clinical pharmacy service practice in a Chinese tertiary hospital. Drug Metab Pers Ther 2016; 30:215-30. [PMID: 26457791 DOI: 10.1515/dmpt-2015-0009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 09/01/2015] [Indexed: 12/31/2022]
Abstract
Clinical pharmacy service is focused on the rationality and safety of medication therapy. Clinical pharmacists play an important role in designing therapeutic regimen, preventing medication errors, reducing the incidence of adverse drug reaction, and saving medical costs. Although clinical pharmacy service in China is in its early stage, its development is rapid. In this manuscript, the working model of clinical pharmacists in a Chinese tertiary hospital is introduced, including ward rounds, consultation, stewardship of antimicrobial therapy, drug adverse reaction monitoring, therapeutic drug monitoring, clinical pharmacokinetics and pharmacogenetics, and training system. With the efforts of clinical pharmacists, there will be a significant increase in the optimization of medication therapy and a notable reduction in preventable adverse drug events as well as health-care cost in China.
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Kuzmanovska M, Dimishkovska M, Maleva Kostovska I, Noveski P, Sukarova Stefanovska E, Plaseska-Karanfilska D. CYP2D6 allele distribution in Macedonians, Albanians and Romanies in the Republic of Macedonia. Balkan J Med Genet 2015; 18:49-58. [PMID: 27785397 PMCID: PMC5026269 DOI: 10.1515/bjmg-2015-0086] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Cytochrome P450 2D6 (CYP2D6) is an enzyme of great importance for the metabolism of clinically used drugs. More than 100 variants of the CYP2D6 gene have been identified so far. The aim of this study was to investigate the allele distribution of CYP2D6 gene variants in 100 individuals of each of the Macedonian, Albanian and Romany population, by genotyping using long range polymerase chain reaction (PCR) and a multiplex single base extension method. The most frequent variants and almost equally distributed in the three groups were the fully functional alleles *1 and *2. The most common non functional allele in all groups was *4 that was found in 22.5% of the Albanians. The most common allele with decreased activity was *41 which was found in 23.0% of the Romany ethnic group, in 11.0% of the Macedonians and in 10.5% of the Albanians. Seven percent of the Albanians, 6.0% of the Romani and 4.0% of the Macedonians were poor metabolizers, while 5.0% of the Macedonians, 1.0% of Albanians and 1.0% of the Romanies were ultrarapid metabolizers. We concluded that the CYP2D6 gene locus is highly heterogeneous in these groups and that the prevalence of the CYP2D6 allele variants and genotypes in the Republic of Macedonia is in accordance with that of other European populations.
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Effect of 22 Novel Cytochrome P450 2D6 (CYP2D6) Variants Found in the Chinese Population on Hemangeol Metabolism In Vitro. Eur J Drug Metab Pharmacokinet 2015; 41:759-765. [DOI: 10.1007/s13318-015-0307-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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20
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Chin FW, Chan SC, Abdul Rahman S, Noor Akmal S, Rosli R. CYP2D6 Genetic Polymorphisms and Phenotypes in Different Ethnicities of Malaysian Breast Cancer Patients. Breast J 2015; 22:54-62. [DOI: 10.1111/tbj.12518] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Fee Wai Chin
- Genetic Medicine Research Centre; Faculty of Medicine and Health Sciences; Universiti Putra Malaysia; Serdang Selangor Malaysia
| | - Soon Choy Chan
- Perdana University Graduate School of Medicine (PUGSOM); Serdang Selangor Malaysia
| | - Sabariah Abdul Rahman
- Medical Education Unit; Faculty of Medicine; Universiti Teknologi MARA; Batu Caves Selangor Malaysia
- Laboratory of Medical Sciences; Faculty of Medicine; Universiti Teknologi MARA; Sungai Buloh Selangor Malaysia
| | - Sharifah Noor Akmal
- Department of Pathology; Faculty of Medicine; Universiti Kebangsaan Malaysia Medical Centre; Cheras Kuala Lumpur Malaysia
| | - Rozita Rosli
- Genetic Medicine Research Centre; Faculty of Medicine and Health Sciences; Universiti Putra Malaysia; Serdang Selangor Malaysia
- UPM-MAKNA Cancer Research Laboratory; Institute of Bioscience; Universiti Putra Malaysia; Serdang Selangor Malaysia
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21
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Cai J, Dai DP, Geng PW, Wang SH, Wang H, Zhan YY, Huang XX, Hu GX, Cai JP. Effects of 22 Novel CYP2D6 Variants Found in the Chinese Population on the Bufuralol and Dextromethorphan MetabolismsIn Vitro. Basic Clin Pharmacol Toxicol 2015; 118:190-9. [PMID: 26310775 DOI: 10.1111/bcpt.12478] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 08/15/2015] [Indexed: 02/01/2023]
Affiliation(s)
- Jie Cai
- The Key Laboratory of Geriatrics; Beijing Hospital & Beijing Institute of Geriatrics; Ministry of Health; Beijing China
- Department of Pharmacology; School of Pharmacy of Wenzhou Medical University; Wenzhou China
- Department of Pharmacy; Traditional Chinese Medical Hospital of Wenling; Wenling China
| | - Da-Peng Dai
- The Key Laboratory of Geriatrics; Beijing Hospital & Beijing Institute of Geriatrics; Ministry of Health; Beijing China
| | - Pei-Wu Geng
- The Laboratory of Clinical Pharmacy; The People's Hospital of Lishui; Lishui China
| | - Shuang-Hu Wang
- The Laboratory of Clinical Pharmacy; The People's Hospital of Lishui; Lishui China
| | - Hao Wang
- Department of Pharmacology; School of Pharmacy of Wenzhou Medical University; Wenzhou China
| | - Yun-Yun Zhan
- Department of Pharmacology; School of Pharmacy of Wenzhou Medical University; Wenzhou China
| | - Xiang-Xin Huang
- Department of Pharmacology; School of Pharmacy of Wenzhou Medical University; Wenzhou China
| | - Guo-Xin Hu
- Department of Pharmacology; School of Pharmacy of Wenzhou Medical University; Wenzhou China
| | - Jian-Ping Cai
- The Key Laboratory of Geriatrics; Beijing Hospital & Beijing Institute of Geriatrics; Ministry of Health; Beijing China
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Bagheri A, Kamalidehghan B, Haghshenas M, Azadfar P, Akbari L, Sangtarash MH, Vejdandoust F, Ahmadipour F, Meng GY, Houshmand M. Prevalence of the CYP2D6*10 (C100T), *4 (G1846A), and *14 (G1758A) alleles among Iranians of different ethnicities. Drug Des Devel Ther 2015; 9:2627-34. [PMID: 25999696 PMCID: PMC4435087 DOI: 10.2147/dddt.s79709] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The presence of polymorphisms in the CYP2D6 gene may modulate enzyme level and activity, thereby affecting individual responses to pharmacological treatment. Here, we compared the prevalence of the CYP2D6*10, *4, and 14* alleles in an Iranian population of different ethnicities with those of other populations. Allele and genotype frequency distributions of CYP2D6*10 variants and predicted phenotypes including extensive metabolizers, intermediate metabolizers, and poor metabolizers were analysed in blood samples of 300 unrelated healthy individuals in an Iranian population using polymerase chain reaction (PCR)-restriction fragment length polymorphism, PCR-single-strand conformation polymorphism, and direct genomic DNA sequencing. The CYP2D6*4 (G1846A) and *14 (G1758A) allelic frequencies were not detected in different ethnicities, demonstrating the absence of a significant contribution of these alleles in Iranian populations. However, the T/T, C/T, and C/C genotype frequencies of the CYP2D6*10 allele were significantly different (P<0.01) in all Iranian ethnic groups. Additionally, the frequency of the homozygous T/T variant of the CYP2D6*10 allele was significantly high in the Lure (P<0.017) and low in the Kurd (P<0.002) ethnicities. The frequency of the T/T variant of the CYP2D6*10 allele in central Iran was the highest (P<0.001), while the south of Iran had the lowest frequency (P<0.001). The frequency of the C/T variant of the CYP2D6*10 allele was significantly a bit high (P<0.001) in females compare to males, while the frequencies of the T/T variant in females is similar to males, which are 24.4% and 24.3%, respectively. In contrast to absence of the CYP2D6*4 (G1846A) and *14 (G1758A) alleles in Iranian populations of different ethnicities, the prediction of the CYP2D6*10 allele is required in drug research and routine treatment, where the information would be helpful for clinicians to optimize therapy or identify persons at risk of adverse drug reactions before clinical trials. Approximately 39.3% of subjects (24.3% homozygous T/T CYP2D6*10 as poor metabolizers and 15% heterozygous C/T CYP2D6*10 as intermediate metabolizers) had this allele; therefore, the harmful effects of drugs are relatively common among Iranians.
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Affiliation(s)
- Ali Bagheri
- Department of Biology, University of Sistan and Baluchestan, Zahedan, Iran
| | - Behnam Kamalidehghan
- Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Maryam Haghshenas
- Department of Biology, Pardis International Unit, University of Guilan, Rasht, Iran
| | - Parisa Azadfar
- Department of Biology, Science and Research Branch, Azad University, Tehran, Iran
| | - Leila Akbari
- Department of Biology, Science and Research Branch, Azad University, Tehran, Iran
| | | | | | - Fatemeh Ahmadipour
- Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Goh Yong Meng
- Department of Animal Science, Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, Malaysia
| | - Massoud Houshmand
- Medical Genetics Department, Special Medical Center, National Institute for Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran ; Medical Genetics Department, National Institute for Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
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Lazalde-Ramos BP, Martínez-Fierro MDLL, Galaviz-Hernández C, Garza-Veloz I, Naranjo MEG, Sosa-Macías M, Llerena A. CYP2D6 gene polymorphisms and predicted phenotypes in eight indigenous groups from northwestern Mexico. Pharmacogenomics 2014; 15:339-48. [PMID: 24533713 DOI: 10.2217/pgs.13.203] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AIM Polymorphisms in CYP2D6 impact the interindividual and interethnic variability of drug efficiency; therefore, we determined the CYP2D6 allele distribution in eight Amerindian groups from northwestern Mexico and compared them with the frequencies in Mexican Mestizos. MATERIALS & METHODS A total of 508 Amerindians were studied. Genotyping of CYP2D6*5 and multiplication alleles was performed by long-range PCR, while CYP2D6*2, *3, *4, *6, *10, *17, *29, *35, *41 and copy number were evaluated by real-time PCR. RESULTS The most frequent alleles were CYP2D6*2 (0.05-0.28), CYP2D6*4 (0.003-0.21) and multiplications (0.043-0.107). CYP2D6*5, *6, * 10 and *41 were not observed in the majority of Amerindians, and CYP2D6*3, *17, *35 and *29 were not detected. The poor metabolizer genotype ( *4/*5) was lower (0.2%) in Amerindians than in Mestizos (5%); conversely, the ultrarapid metabolizer genotype was higher (12.6%) in indigenous groups than in Mestizos (7%). CONCLUSION Our data show a lower frequency of CYP2D6 inactive alleles and a higher frequency of duplication/multiplication of CYP2D6 active alleles in indigenous populations that in Mestizos. Original submitted 14 August 2013; Revision submitted 7 October 2013.
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Affiliation(s)
- Blanca Patricia Lazalde-Ramos
- Laboratorio de Medicina Molecular, Unidad Académica de Ciencias Químicas, Universidad Autónoma de Zacatecas, Zacatecas, México
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24
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LLerena A, Naranjo MEG, Rodrigues-Soares F, Penas-LLedó EM, Fariñas H, Tarazona-Santos E. Interethnic variability ofCYP2D6alleles and of predicted and measured metabolic phenotypes across world populations. Expert Opin Drug Metab Toxicol 2014; 10:1569-83. [DOI: 10.1517/17425255.2014.964204] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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25
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Sosa-Macías M, Llerena A. Cytochrome P450 genetic polymorphisms of Mexican indigenous populations. ACTA ACUST UNITED AC 2014; 28:193-208. [PMID: 24145057 DOI: 10.1515/dmdi-2013-0037] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 09/02/2013] [Indexed: 11/15/2022]
Abstract
This review focuses on the genetic polymorphisms of the cytochrome P450 (CYP) genes in Mexican indigenous populations, who are a part of the wide ethnic diversity of this country. These native groups have a particular historical trajectory that is different from the Mexican Mestizos. This variability may be reflected in the frequency distribution of polymorphisms in the CYP genes that encode enzymes involved in the metabolism of drugs and other xenobiotics. Therefore, these polymorphisms may affect drug efficacy and safety in indigenous populations in Mexico. The present study aimed to analyze the prevalence of CYP polymorphisms in indigenous Mexicans and to compare the results with studies in Mexican Mestizos. Because the extrapolation of pharmacogenetic data from Mestizos is not applicable to the majority of indigenous groups, pharmacogenetic studies directed at indigenous populations need to be developed. The Amerindians analyzed in this study showed a low phenotypic (CYP2D6) and genotypic (CYP2D6, CYP2C9) diversity, unlike Mexican Mestizos. The frequency of polymorphisms in the CYP1A1, CYP2C19, CYP2E1, and CYP3A4 genes was more similar among the Amerindians and Mexican Mestizos, with the exception of the CYP1A2 gene, whose *1F variant frequency in Mexican Amerindians was the highest described to date.
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26
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Alcazar-González GA, Calderón-Garcidueñas AL, Garza-Rodríguez ML, Rubio-Hernández G, Escorza-Treviño S, Olano-Martin E, Cerda-Flores RM, Castruita-Avila AL, González-Guerrero JF, le Brun S, Simon-Buela L, Barrera-Saldaña HA. Comparative study of polymorphism frequencies of the CYP2D6, CYP3A5, CYP2C8 and IL-10 genes in Mexican and Spanish women with breast cancer. Pharmacogenomics 2014; 14:1583-92. [PMID: 24088129 DOI: 10.2217/pgs.13.83] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
AIM Pharmacogenetic studies in breast cancer (BC) may predict the efficacy of tamoxifen and the toxicity of paclitaxel and capecitabine. We determined the frequency of polymorphisms in the CYP2D6 gene associated with activation of tamoxifen, and those of the genes CYP2C8, CYP3A5 and DPYD associated with toxicity of paclitaxel and capecitabine. We also included a IL-10 gene polymorphism associated with advanced tumor stage at diagnosis. PATIENTS & METHODS Genomic DNAs from 241 BC patients from northeast Mexico were genotyped using DNA microarray technology. RESULTS For tamoxifen processing, CYP2D6 genotyping predicted that 90.8% of patients were normal metabolizers, 4.2% ultrarapid, 2.1% intermediate and 2.9% poor metabolizers. For paclitaxel and the CYP2C8 gene, 75.3% were normal, 23.4% intermediate and 1.3% poor metabolizers. Regarding the DPYD gene, only one patient was a poor metabolizer. For the IL-10 gene, 47.1% were poor metabolizers. CONCLUSION These results contribute valuable information towards personalizing BC chemotherapy in Mexican women.
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Tharanga TDP, Jinadasa CMV, Risama MF, Galappatthy P, Jayakody RL, Dissanayake VHW. Genetic variants in the cytochrome P450 2D6 gene in the Sri Lankan population. INDIAN JOURNAL OF HUMAN GENETICS 2014; 19:392-6. [PMID: 24497701 PMCID: PMC3897131 DOI: 10.4103/0971-6866.124361] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
INTRODUCTION: Cytochrome P450 2D6 (CYP2D6) enzymes are involved in the metabolism of a large number of commonly prescribed drugs such as antidepressants and cardiovascular drugs. The CYP2D6 *3, *4 and *14 variants associated with the loss of enzyme function; CYP2D6 *10 and *17 variants with reduced enzyme function; and CYP2D6 *2 variant with no effect on enzyme function. Establishing the frequency of these variant alleles in Sri Lankan population would be useful for optimizing pharmacotherapy with CYP2D6-substrate drugs. OBJECTIVE: The objective of this study was to determine the prevalence of CYP2D6 *2, *3, *4, *10, *14 and *17 variants in the main ethnic groups in the Sri Lankan population. MATERIALS AND METHODS: A total of 90 deoxyribonucleic acid (DNA) samples (30 each from Sinhalese, Tamils and Moors) were selected from a DNA resource at the Human Genetic Unit, Faculty of Medicine, University of Colombo. This collection had been made for population genetic studies from a random population based volunteers. Genotyping was performed using published polymerase chain reaction/restriction fragment length polymorphism methods. RESULTS: The prevalence of the CYP2D6 variants in Sinhalese, Sri Lankan Tamils and Moors respectively were CYP2D6 *2: 37%, 41.6% and 37.9%; CYP2D6 *3: 60.3%, 45% and 30%; CYP2D6 *4: 21.6%, 6.6% and 8.3%; CYP2D6 *10: 40%, 35% and 44%. CYP2D6 *14 and *17 variants were not identified. CONCLUSION: CYP2D6*3, *4 and *10 variants, which are associated with reduced or loss of CYP2D6 enzyme function were found in our population in significant frequencies. CYP2D6*4, which is reported to be a Caucasian variant was also found in all three ethnic groups.
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Affiliation(s)
- T D Praveen Tharanga
- Department of Pharmacology, Faculty of Medicine, University of Colombo, Colombo 00800, Sri Lanka
| | - C M V Jinadasa
- Department of Human Genetics Unit, Faculty of Medicine, University of Colombo, Colombo 00800, Sri Lanka
| | - M F Risama
- Department of Human Genetics Unit, Faculty of Medicine, University of Colombo, Colombo 00800, Sri Lanka
| | | | - R L Jayakody
- Department of Pharmacology, Faculty of Medicine, University of Colombo, Colombo 00800, Sri Lanka
| | - Vajira H W Dissanayake
- Department of Human Genetics Unit, Faculty of Medicine, University of Colombo, Colombo 00800, Sri Lanka
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Ota T, Hayashida M, Ishii M, Iwao-Koizumi K, Murata S, Kinoshita K. Long PCR-based genotyping for a deleted CYP2D6 gene without DNA extraction. Drug Metab Pharmacokinet 2013; 29:283-5. [PMID: 24390472 DOI: 10.2133/dmpk.dmpk-13-nt-116] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In the post-genome era, a simple and inexpensive method for diagnostic analysis is in high demand. Cytochrome P450 (CYP) 2D6 is one of the most widely investigated CYPs in relation to genetic polymorphism. Detection of CYP2D6*5 is difficult since long PCR is used. Especially for samples without DNA extraction, the detection is not sensitive enough for population analysis. Therefore, we developed a CYP2D6*5 genotyping method that involves nested long PCR, directly using human whole saliva as a template without DNA extraction. This method will be very useful for genetic diagnoses and can be an efficient tool for individualization of drug therapy in clinical studies.
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Affiliation(s)
- Tomoko Ota
- School of Pharmaceutical Sciences, Mukogawa Women's University
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29
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Abstract
Cytochrome P450 2D6 (CYP2D6) plays an important role in the metabolism and bioactivation of about 25% of clinically used drugs including many antidepressants, antipsychotics and opioids. CYP2D6 activity is highly variably ranging from no activity in so-called poor metabolizers to ultrarapid metabolism at the other end of the extreme of the activity distribution. A large portion of this variability can be explained by the highly polymorphic nature of the CYP2D6 gene locus for which > 100 variants and subvariants identified to date. Allele frequencies vary markedly between ethnic groups; some have exclusively or predominantly only been observed in certain populations. Pharmacogenetic testing holds the promise of individualizing drug therapy by identifying patients with CYP2D6 diplotypes that puts them at an increased risk of experiencing dose-related adverse events or therapeutic failure. Inferring a patient's CYP2D6 metabolic capacity, or phenotype, however, is a challenging task due to the complexity of the CYP2D6 gene locus. Allelic variation includes SNPs, small insertions and deletions, gene copy number variation and rearrangements with CYP2D7, a highly related non-functional gene. This review provides a summary of the intricacies of CYP2D6 variation and genotype analysis, knowledge that is invaluable for the translation of genotype into clinically useful information.
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Affiliation(s)
- Andrea Gaedigk
- Children's Mercy Hospital and Clinics, Division of Clinical Pharmacology and Innovative Therapeutics , Kansas City, Missouri , USA
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30
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Important and critical scientific aspects in pharmacogenomics analysis: lessons from controversial results of tamoxifen and CYP2D6 studies. J Hum Genet 2013; 58:327-33. [PMID: 23657426 DOI: 10.1038/jhg.2013.39] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Tamoxifen contributes to decreased recurrence and mortality of patients with hormone receptor-positive breast cancer. As this drug is metabolized by phase I and phase II enzymes, the interindividual variations of their enzymatic activity are thought to be associated with individual responses to tamoxifen. Among these enzymes, CYP2D6 is considered to be a rate-limiting enzyme in the generation of endoxifen, a principal active metabolite of tamoxifen, and the genetic polymorphisms of CYP2D6 have been extensively investigated in association with the plasma endoxifen concentrations and clinical outcome of tamoxifen therapy. In addition to CYP2D6, other genetic factors including polymorphisms in various drug-metabolizing enzymes and drug transporters have been implicated to their relations to clinical outcome of tamoxifen therapy, but their effects would be small. Although the results of association studies are controversial, accumulation of the evidence has revealed us the important and critical issues in the tamoxifen pharmacogenomics study, namely the quality of genotyping, the coverage of genetic variations, the criteria for sample collection and the source of DNAs, which are considered to be common problematic issues in pharmacogenomics studies. This review points out common critical issues in pharmacogenomics studies through the lessons we have learned from tamoxifen pharmacogenomics, as well as summarizes the results of pharmacogenomics studies for tamoxifen treatment.
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31
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Sosa-Macías M, Elizondo G, Flores-Pérez C, Flores-Pérez J, Bradley-Alvarez F, Alanis-Bañuelos RE, Lares-Asseff I. CYP2D6Genotype and Phenotype in Amerindians of Tepehuano Origin and Mestizos of Durango, Mexico. J Clin Pharmacol 2013; 46:527-36. [PMID: 16638736 DOI: 10.1177/0091270006287586] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Although the drug-metabolizing enzyme CYP2D6 has been studied extensively in subjects of differing ethnicities, limited CYP2D6 pharmacogenetic data are available for the Amerindian population and Mestizos of Mexico. Dextromethorphan hydroxylation phenotype was studied in Tepehuano Amerindian (n = 58) and Mestizo (n = 88) subjects, and 195 individuals (85 Tepehuano Amerindians and 110 Mestizos) were genotyped by polymerase chain reaction-restriction fragment length polymorphism methods to identify the frequencies of the CYP2D6*3, *4, *6, and *10 alleles. Tepehuano Amerindian subjects lacked the poor metabolizer (PM) phenotype, whereas in Mestizos the PM phenotype frequency was 6.8%. The CYP2D6*3, *6, and *10 alleles were not found in Tepehuano Amerindians. The CYP2D6*4 allele had a low frequency (0.006) in this Amerindian group. In the Mestizo group, the CYP2D6*3, *4, and *10 alleles had frequencies of 0.009, 0.131, and 0.023, respectively. The CYP2D6*6 allele was not found in Mestizos. The genotype-phenotype association was strongly statistically significant (r(2) = .45; P = .005) in Mestizos. The Tepehuano population was found to have a low phenotypic and genotypic CYP2D6 diversity and differed from other Amerindian groups. On the other hand, the frequencies of the CYP2D6 variant alleles in Mestizos were similar to those reported for whites.
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Affiliation(s)
- Martha Sosa-Macías
- Centro Interdisciplinario de Investigación para el Desarrollo Integral Regional del IPN Unidad Durango, CIIDIR-IPN, México
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Effect of CYP2D6*10 and APOE Polymorphisms on the Efficacy of Donepezil in Patients With Alzheimer’s Disease. Am J Med Sci 2013; 345:222-6. [DOI: 10.1097/maj.0b013e318255a8f9] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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33
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Suzumura T, Kimura T, Kudoh S, Umekawa K, Nagata M, Matsuura K, Tanaka H, Mitsuoka S, Yoshimura N, Kira Y, Nakai T, Hirata K. Reduced CYP2D6 function is associated with gefitinib-induced rash in patients with non-small cell lung cancer. BMC Cancer 2012. [PMID: 23207012 PMCID: PMC3536666 DOI: 10.1186/1471-2407-12-568] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background Rash, liver dysfunction, and diarrhea are known major adverse events associated with erlotinib and gefitinib. However, clinical trials with gefitinib have reported different proportions of adverse events compared to trials with erlotinib. In an in vitro study, cytochrome P450 (CYP) 2D6 was shown to be involved in the metabolism of gefitinib but not erlotinib. It has been hypothesized that CYP2D6 phenotypes may be implicated in different adverse events associated with gefitinib and erlotinib therapies. Methods The frequency of each adverse event was evaluated during the period in which the patients received gefitinib or erlotinib therapy. CYP2D6 phenotypes were determined by analysis of CYP2D6 genotypes using real-time polymerase chain reaction techniques, which can detect single-nucleotide polymorphisms. The CYP2D6 phenotypes were categorized into 2 groups according to functional or reduced metabolic levels. In addition, we evaluated the odds ratio (OR) of the adverse events associated with each factor, including CYP2D6 activities and treatment types. Results A total of 232 patients received gefitinib therapy, and 86 received erlotinib therapy. Reduced function of CYP2D6 was associated with an increased risk of rash of grade 2 or more (OR, 0.44; 95% confidence interval [CI], 0.21–0.94; *p = 0.03), but not diarrhea ≥ grade 2 (OR, 0.49; 95% CI, 0.17–1.51; *p = 0.20) or liver dysfunction ≥ grade 2 (OR, 1.08; 95% CI, 0.52–2.34; *p = 0.84) in the gefitinib cohort. No associations were observed between any adverse events in the erlotinib cohort and CYP2D6 phenotypes (rash: OR, 1.77; 95% CI, 0.54–6.41; *p = 0.35/diarrhea: OR, 1.08; 95% CI, 0.21–7.43; *p = 0.93/liver dysfunction: OR, 0.93; 95% CI, 0.20–5.07; *p = 0.93). Conclusions The frequency of rash was significantly higher in patients with reduced CYP2D6 activity who treated with gefitinib compared to patients with functional CYP2D6. CYP2D6 phenotypes are a risk factor for the development of rash in response to gefitinib therapy.
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Affiliation(s)
- Tomohiro Suzumura
- Department of Respiratory Medicine, Graduate School of Medicine, Osaka City University, Osaka, Japan
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Zihlif M, Imraish A, Irshaid YM. Frequency of certain single-nucleotide polymorphisms and duplication of CYP2D6 in the Jordanian population. Genet Test Mol Biomarkers 2012; 16:1201-5. [PMID: 22905959 DOI: 10.1089/gtmb.2012.0122] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The CYP2D6 isozymes are responsible for metabolism of 7-10% of clinically available drugs. Genetic polymorphism in CYP2D6 may have an impact on drug efficacy and toxicity. The aim of this study was to determine the allelic frequency of CYP2D6*4, *10, and *17 and CYP2D6*2×N duplication allele in 192 healthy unrelated male and female Jordanian volunteers. Polymerase chain reaction (PCR)-restriction fragment length polymorphism-based methods were used to identify the CYP2D6*4, *10, and *17 genotypes; and allele-specific long PCR was used to determine the CYP2D6*2×N allelic frequency. The CYP2D6*10 allele was the most frequent mutant allele in Jordanians (14.8%) followed by CYP2D6*4 and *17 at 12.8%, and 8.3%, respectively. The duplication allele was found in 13.5% of the studied sample. The CYP2D6*4 G-A heterozygote genotype frequency was 20.3%, and the homozygous mutant genotype was 2.6%. In case of CYP2D6*10 C-T and CYP2D6*17 G-C heterozygote genotypes, the frequencies were 21.4% and 12.5%, respectively, while the homozygous mutant genotype frequencies of T-T and C-C were 4.2% and 2.1%, respectively. In conclusion, the allelic distributions of the CYP2D6 gene among Jordanians are different from other Mediterranean groups, especially the *10 and *17 single-nucleotide polymorphisms, and more importantly the CYP2D6*2×N duplication allele, which seems to follow a gradient reduction in prevalence from Ethiopia to Northern Europe.
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Affiliation(s)
- Malek Zihlif
- Department of Pharmacology, University of Jordan, Amman, Jordan.
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35
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Kiyotani K, Mushiroda T, Nakamura Y, Zembutsu H. Pharmacogenomics of Tamoxifen: Roles of Drug Metabolizing Enzymes and Transporters. Drug Metab Pharmacokinet 2012; 27:122-31. [DOI: 10.2133/dmpk.dmpk-11-rv-084] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Chiba K, Kato M, Ito T, Suwa T, Sugiyama Y. Inter-individual Variability of In Vivo CYP2D6 Activity in Different Genotypes. Drug Metab Pharmacokinet 2012; 27:405-13. [DOI: 10.2133/dmpk.dmpk-11-rg-078] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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37
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Teh LK, Bertilsson L. Pharmacogenomics of CYP2D6: molecular genetics, interethnic differences and clinical importance. Drug Metab Pharmacokinet 2011; 27:55-67. [PMID: 22185816 DOI: 10.2133/dmpk.dmpk-11-rv-121] [Citation(s) in RCA: 150] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
CYP2D6 has received intense attention since the beginning of the pharmacogenetic era in the 1970s. This is because of its involvement in the metabolism of more than 25% of the marketed drugs, the large geographical and inter-ethnic differences in the genetic polymorphism and possible drug-induced toxicity. Many interesting reviews have been published on CYP2D6 and this review aims to reinstate the importance of the genetic polymorphism of CYP2D6 in different populations as well as some clinical implications and important drug interactions.
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Affiliation(s)
- Lay Kek Teh
- Pharmacogenomics Centre PROMISE, Faculty of Pharmacy, Universiti Teknologi MARA, Selangor DE, Malaysia.
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Kurose K, Sugiyama E, Saito Y. Population differences in major functional polymorphisms of pharmacokinetics/pharmacodynamics-related genes in Eastern Asians and Europeans: implications in the clinical trials for novel drug development. Drug Metab Pharmacokinet 2011; 27:9-54. [PMID: 22123129 DOI: 10.2133/dmpk.dmpk-11-rv-111] [Citation(s) in RCA: 181] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Drug lag, recently discussed extensively in Japan, can be divided into two phases: clinical development time and application review time. The former factor is still an important problem that might be improved by promoting multi-regional clinical trials and considering the results from other similar populations with Japanese, such as Koreans and Chinese. In this review, we compare the allelic or genotype frequencies of 30 relatively common functional alleles mainly between Eastern Asians and Europeans as well as among 3 major populations in Eastern Asian countries, Japan, Korea, and China, in 12 pharmacokinetics (PK)/pharmacodynamics (PD)-related genes; CYP2C9 (*2 and *3), CYP2C19 (*2, *3 and *17), 13 CYP2D6 haplotypes including *4, *5 and *10, CYP3A5 (*3), UGT1A1 (*28 and *6), NAT2 (*5, *6 and *7), GSTM1 and GSTT1 null genotypes, SLCO1B1 521T>C, ABCG2 421C>A, and HLA-A*31:01 and HLA-B*58:01. In this review, differences in allele frequencies (AFs) or genotype frequencies (GFs) less than 0.1 (in the cases of highest AF (GF) ≥0.1) or less than 0.05 (in the cases of lowest AF (GF) <0.1) were regarded as similar. Between Eastern Asians and Europeans, AFs (or GFs) are regarded as being different for many alleles such as CYP2C9 (*2), CYP2C19 (*2, *3 and *17), CYP2D6 (*4 and *10), CYP3A5 (*3), UGT1A1 (*28 and *6), NAT2 (*5*7), GSTT1 null and ABCG2 421C>A. Among the 3 Eastern Asian populations, however, only AFs of CYP2C19*3, CYP2D6*10, HLA-A*31:01 and HLA-B*58:01 are regarded as dissimilar. For CYP2C19*3, the total functional impact on CYP2C19 could be small if the frequencies of the two null alleles CYP2C19*2 and *3 are combined. Regarding CYP2D6*10, frequency difference over 0.1 is observed only between Japanese and Chinese (0.147). Although environmental factors should be considered for PK/PD differences, we could propose that among Japan, Korea, and China, genetic differences are very small for the analyzed common PK-related gene polymorphisms. On the other hand, AFs of the two HLA alleles important for cutaneous adverse drug reactions are diverse even among Eastern Asians and thus should be taken into account.
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Affiliation(s)
- Kouichi Kurose
- Division of Medicinal Safety Science, National Institute of Health Sciences, Tokyo, Japan
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Next-day residual sedative effect after nighttime administration of an over-the-counter antihistamine sleep aid, diphenhydramine, measured by positron emission tomography. J Clin Psychopharmacol 2010; 30:694-701. [PMID: 21105284 DOI: 10.1097/jcp.0b013e3181fa8526] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Antihistamines often are self-administered at night as over-the-counter (OTC) sleep aids, but their next-day residual sedative effect has never been evaluated using a reliable quantitative method such as positron emission tomography (PET). We performed a double-blind, placebo-controlled, crossover study in which we evaluated the residual effect the next day after nighttime administration of diphenhydramine, a commonly used OTC sleep aid, in terms of brain H₁ receptor occupancy (H₁RO) measured using ¹¹C-doxepin-PET. We also compared the results of diphenhydramine with those of bepotastine, a second-generation antihistamine. Eight healthy adult male subjects underwent PET measurement the morning (11:00) after random oral administration of diphenhydramine (50 mg), bepotastine (10 mg), or placebo the night before (23:00). Binding potential ratios and H₁ROs were calculated in different brain regions of interest such as the cingulate gyrus, frontotemporal cortex, and cerebellum. Subjective sleepiness and plasma drug concentration also were measured. Calculation of binding potential ratios revealed significantly lower values for diphenhydramine than for bepotastine or placebo in all regions of interest (P < 0.01). Cortical mean H₁RO after diphenhydramine treatment was 44.7% compared with 16.6% for bepotastine treatment (P < 0.01). Subjective sleepiness was not significantly different among the subjects treated with each test drug or the placebo. In conclusion, the next-day residual sedative effect after nighttime administration of the OTC sleep aid diphenhydramine was verified for the first time by direct PET measurement of H₁RO. Taking into account the possible hangover effect of OTC antihistamine sleep aids, care needs to be taken during their administration.
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Limited effects of frequent CYP2D6*36-*10 tandem duplication allele on in vivo dextromethorphan metabolism in a Japanese population. Eur J Clin Pharmacol 2010; 66:1065-8. [DOI: 10.1007/s00228-010-0876-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Accepted: 07/19/2010] [Indexed: 11/27/2022]
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41
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Yagihashi T, Mizuno M, Chino B, Sato Y, Sakuma K, Takebayashi T, Takao T, Kosaki K. Effects of the CYP2D6*10 alleles and co-medication with CYP2D6-dependent drugs on risperidone metabolism in patients with schizophrenia. Hum Psychopharmacol 2009; 24:301-8. [PMID: 19387994 DOI: 10.1002/hup.1025] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE Risperidone is converted to 9-hydroxyrisperidone by CYP2D6. Two parameters were used to examine the influences of CYP2D6 polymorphism and of co-medication on risperidone metabolism: the risperidone:9-hydroxyrisperidone concentration ratio (R:9-OHR ratio) and the sum of the risperidone and 9-hydroxyrisperidone concentrations divided by the dose (C:D ratio). We evaluated the effect of the CYP2D6*10 allele, which is a prevalent mutant allele among East Asians. METHODS Genotyping using the P450 microarray system was performed for 89 Japanese patients with schizophrenia receiving risperidone. The patients with CYP2D6*1/*1, *1/*2, or *2/*2 were classified as Group 1, those with one CYP2D6*10 allele (CYP2D6*1/*10 or *2/*10) were classified as Group 2, and those with two CYP2D6*10 alleles were classified as Group 3. The R:9-OHR and C:D ratios were analyzed using two-way ANOVAs with the CYP2D6 genotype and co-medication with CYP2D6-dependent drugs as independent variables. RESULTS Both the "genotype" and the "co-medication" factors had significant impacts on the R:9-OHR ratio (p = 0.011, p < 0.001). The "genotype" factor also had a significant impact on the C:D ratio (p = 0.032). However, the "co-medication" factor did not have a significant impact on the C:D ratio (p = 0.129). CONCLUSIONS The CYP2D6*10 polymorphism and the presence of co-medication exerted significant influences on the pharmacokinetics of risperidone.
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Affiliation(s)
- Tatsuhiko Yagihashi
- Department of Pediatrics, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
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Safety and tolerability of atomoxetine over 3 to 4 years in children and adolescents with ADHD. J Am Acad Child Adolesc Psychiatry 2009; 48:176-85. [PMID: 20040824 DOI: 10.1097/chi.0b013e318193060e] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To assess the long-term safety and tolerability of atomoxetine hydrochloride in children and adolescents with attention-deficit/hyperactivity disorder treated for > or = 3 years. METHOD Data from 13 double-blind, placebo-controlled trials and 3 open-label extension studies were pooled. Outcome measures were patient-reported treatment-emergent adverse events (AEs); discontinuations due to AEs, serious AEs, and changes in body weight, height, vital signs, electrocardiogram, and hepatic function tests. RESULTS In total, 714 patients were treated with atomoxetine for > or = 3 years (mean follow-up 4.8 years [SD 1.1 years]), including a subset of 508 treated for > or = 4 years (mean follow-up 5.3 years [SD 0.8 years]). Most subjects were younger than 12 years at entry (73.8%), male (78.4%), and white (88.9%). The mean final daily dose of atomoxetine was 1.35 mg/kg (SD 0.37 mg/kg). No new or unexpected AEs were observed compared with acute-phase treatment. Less than 6% of patients exhibited aggressive/hostile behaviors, and less than 1.6% reported suicidal ideation/behavior. No clinically significant effects were seen on growth rate, vital signs, or electrocardiographic parameters, and < or = 2% of patients showed potentially clinically significant hepatic changes. CONCLUSION Atomoxetine was safe and well tolerated for children and adolescents with > or = 3 and/or > or = 4 years of treatment.
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Matsunaga M, Yamazaki H, Kiyotani K, Iwano S, Saruwatari J, Nakagawa K, Soyama A, Ozawa S, Sawada JI, Kashiyama E, Kinoshita M, Kamataki T. Two Novel CYP2D6*10 Haplotypes As Possible Causes of a Poor Metabolic Phenotype in Japanese. Drug Metab Dispos 2009; 37:699-701. [DOI: 10.1124/dmd.108.026096] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Neafsey P, Ginsberg G, Hattis D, Sonawane B. Genetic polymorphism in cytochrome P450 2D6 (CYP2D6): Population distribution of CYP2D6 activity. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2009; 12:334-61. [PMID: 20183526 DOI: 10.1080/10937400903158342] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Cytochrome P-450 2D6 (CYP2D6) is involved in the metabolism of many therapeutic drugs even though the enzyme represents a small proportion of the total CYP content of human liver. In vivo phenotyping with probe drug substrates such as debrisoquine and dextromethorphan showed a clear separation between poor metabolizers (PM) and extensive metabolizers (EM). This polymorphism may affect susceptibility to environmental disease, as suggested by molecular epidemiologic studies that found an association between CYP2D6 metabolizer phenotype and cancer risk; however, this association is not consistent. There are only a few examples of CYP2D6 involvement in toxicant mechanism of action, but this has not been extensively studied. Gene probe studies documented a number of genetic polymorphisms that underlie CYP2D6 metabolizer phenotypes. The EM group carries the wild-type (*1) or active (*2) variant alleles, while the PM group carries the *3, *4, *5, or *6 alleles, all of which code for a protein that has lower or null CYP2D6 activity. The current analysis characterizes (a) influence of genotype on phenotype based upon in vivo metabolism studies of probe drugs and (b) frequency of the major genotypes in different population groups is also characterized. These data were then incorporated into Monte Carlo modeling to simulate population distributions of CYP2D6 activity. This analysis reproduced the bimodal distributions commonly seen in phenotyping studies of Caucasians and found extensive population variability in enzyme activity, as indicated by the 9- to 56-fold difference between the PM modal median and the total population median CYP2D6 activity. This substantial degree of interindividual variability in CYP function indicates that assessments involving CYP2D6 substrates need to consider the full distribution of enzyme activity in refining estimates of internal dose in health assessments of xenobiotics.
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Ginsberg G, Smolenski S, Neafsey P, Hattis D, Walker K, Guyton KZ, Johns DO, Sonawane B. The influence of genetic polymorphisms on population variability in six xenobiotic-metabolizing enzymes. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2009; 12:307-333. [PMID: 20183525 DOI: 10.1080/10937400903158318] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This review provides variability statistics for polymorphic enzymes that are involved in the metabolism of xenobiotics. Six enzymes were evaluated: cytochrome P-450 (CYP) 2D6, CYP2E1, aldehyde dehydrogenase-2 (ALDH2), paraoxonase (PON1), glutathione transferases (GSTM1, GSTT1, and GSTP1), and N-acetyltransferases (NAT1 and NAT2). The polymorphisms were characterized with respect to (1) number and type of variants, (2) effects of polymorphisms on enzyme function, and (3) frequency of genotypes within specified human populations. This information was incorporated into Monte Carlo simulations to predict the population distribution and describe interindividual variability in enzyme activity. The results were assessed in terms of (1) role of these enzymes in toxicant activation and clearance, (2) molecular epidemiology evidence of health risk, and (3) comparing enzyme variability to that commonly assumed for pharmacokinetics. Overall, the Monte Carlo simulations indicated a large degree of interindividual variability in enzyme function, in some cases characterized by multimodal distributions. This study illustrates that polymorphic metabolizing systems are potentially important sources of pharmacokinetic variability, but there are a number of other factors including blood flow to liver and compensating pathways for clearance that affect how a specific polymorphism will alter internal dose and toxicity. This is best evaluated with the aid of physiologically based pharmacokinetic (PBPK) modeling. The population distribution of enzyme activity presented in this series of articles serves as inputs to such PBPK modeling analyses.
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Affiliation(s)
- Gary Ginsberg
- Connecticut Department of Public Health, Hartford, 06134, USA.
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Sakuyama K, Sasaki T, Ujiie S, Obata K, Mizugaki M, Ishikawa M, Hiratsuka M. Functional Characterization of 17CYP2D6Allelic Variants (CYP2D6.2, 10, 14A–B, 18, 27, 36, 39, 47–51, 53–55, and 57). Drug Metab Dispos 2008; 36:2460-7. [DOI: 10.1124/dmd.108.023242] [Citation(s) in RCA: 122] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Otani K, Ujike H, Sakai A, Okahisa Y, Kotaka T, Inada T, Harano M, Komiyama T, Hori T, Yamada M, Sekine Y, Iwata N, Iyo M, Sora I, Ozaki N, Kuroda S. Reduced CYP2D6 activity is a negative risk factor for methamphetamine dependence. Neurosci Lett 2008; 434:88-92. [PMID: 18280655 DOI: 10.1016/j.neulet.2008.01.033] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2007] [Revised: 01/12/2008] [Accepted: 01/15/2008] [Indexed: 11/26/2022]
Abstract
Because methamphetamine (METH) is metabolized by CYP2D6 at the first step of hydroxylation and demethylation, it is possible that functional variants of CYP2D6 alter susceptibility to methamphetamine-induced dependence. We genotyped CYP2D6*1, *4, *5, *10, and *14 for 202 patients with METH dependence and 337 controls in a Japanese population and found a significant association of the CYP2D6 gene with METH dependence (p=0.0299). The patients had fewer *10 and *14 alleles, which are hypofunction alleles, than the controls. CYP2D6 genotypes were divided into three phenotypes: extensive metabolizers, intermediate metabolizers, and poor metabolizers. There was no poor metabolizer among our Japanese subjects, and intermediate metabolizers of CYP2D6 were significantly fewer in methamphetamine-dependent subjects than in controls (p=0.0212), with an odds ratio of 0.62 (95% confidence interval: 0.51-0.76). The present study demonstrated that reduced CYP2D6 activity was a negative risk factor for methamphetamine dependence.
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Affiliation(s)
- Kyohei Otani
- Department of Neuropsychiatry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Shikata-cho 2-5-1, Okayama 700-8558, Japan
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Gaedigk A, Simon SD, Pearce RE, Bradford LD, Kennedy MJ, Leeder JS. The CYP2D6 Activity Score: Translating Genotype Information into a Qualitative Measure of Phenotype. Clin Pharmacol Ther 2007; 83:234-42. [DOI: 10.1038/sj.clpt.6100406] [Citation(s) in RCA: 561] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Shen H, He MM, Liu H, Wrighton SA, Wang L, Guo B, Li C. Comparative metabolic capabilities and inhibitory profiles of CYP2D6.1, CYP2D6.10, and CYP2D6.17. Drug Metab Dispos 2007; 35:1292-300. [PMID: 17470523 DOI: 10.1124/dmd.107.015354] [Citation(s) in RCA: 129] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Polymorphisms in the cytochrome P450 2D6 (CYP2D6) gene are a major cause of pharmacokinetic variability in human. Although the poor metabolizer phenotype is known to be caused by two null alleles leading to absence of functional CYP2D6 protein, the large variability among individuals with functional alleles remains mostly unexplained. Thus, the goal of this study was to examine the intrinsic enzymatic differences that exist among the several active CYP2D6 allelic variants. The relative catalytic activities (enzyme kinetics) of three functionally active human CYP2D6 allelic variants, CYP2D6.1, CYP2D6.10, and CYP2D6.17, were systematically investigated for their ability to metabolize a structurally diverse set of clinically important CYP2D6-metabolized drugs [atomoxetine, bufuralol, codeine, debrisoquine, dextromethorphan, (S)-fluoxetine, nortriptyline, and tramadol] and the effects of various CYP2D6-inhibitors [cocaine, (S)-fluoxetine, (S)-norfluoxetine, imipramine, quinidine, and thioridazine] on these three variants. The most significant difference observed was a consistent but substrate-dependent decease in the catalytic efficiencies of cDNA-expressed CYP2D6.10 and CYP2D6.17 compared with CYP2D6.1, yielding 1.32 to 27.9 and 7.33 to 80.4% of the efficiency of CYP2D6.1, respectively. The most important finding from this study is that there are mixed effects on the functionally reduced allelic variants in enzyme-substrate affinity or enzyme-inhibitor affinity, which is lower, higher, or comparable to that for CYP2D6.1. Considering the rather high frequencies of CYP2D6*10 and CYP2D6*17 alleles for Asians and African Americans, respectively, these data provide further insight into ethnic differences in CYP2D6-mediated drug metabolism. However, as with all in vitro to in vivo extrapolations, caution should be applied to the clinical consequences.
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Affiliation(s)
- Hongwu Shen
- Shanghai Institute of Materia Medica, Graduate School, Chinese Academy of Sciences, Zhangjiang Hi-Tech Park, Shanghai, China
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Shanks N, Pyles RA. Evolution and medicine: the long reach of "Dr. Darwin". Philos Ethics Humanit Med 2007; 2:4. [PMID: 17407602 PMCID: PMC1852567 DOI: 10.1186/1747-5341-2-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2006] [Accepted: 04/03/2007] [Indexed: 05/14/2023] Open
Abstract
In this review we consider the new science of Darwinian medicine. While it has often been said that evolutionary theory is the glue that holds the disparate branches of biological inquiry together and gives them direction and purpose, the links to biomedical inquiry have only recently been articulated in a coherent manner. Our aim in this review is to make clear first of all, how evolutionary theory is relevant to medicine; and secondly, how the biomedical sciences have enriched our understanding of evolutionary processes. We will conclude our review with some observations of the philosophical significance of this interplay between evolutionary theory and the biomedical sciences.
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Affiliation(s)
- Niall Shanks
- Departments of History and of Philosophy, Wichita State University, Wichita, Kansas 67260, USA
| | - Rebecca A Pyles
- Honors College and Department of Biological Sciences, East Tennessee State University, Johnson City, Tennessee 37614, USA
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