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Holail J, Mobarak R, Al-Ghamdi B, Aljada A, Fakhoury H. Association of VKORC1 and CYP2C9 single-nucleotide polymorphisms with warfarin dose adjustment in Saudi patients. Drug Metab Pers Ther 2022; 37:353-359. [PMID: 36476275 DOI: 10.1515/dmpt-2022-0108] [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: 01/24/2022] [Accepted: 02/14/2022] [Indexed: 12/13/2022]
Abstract
OBJECTIVES Despite its wide usage, warfarin therapy remains challenging due to its narrow therapeutic index, inter-individual response variability, and risk of bleeding. Previous reports have suggested that polymorphisms in VKORC1 and CYP2C9 genes could influence warfarin therapy. Herein, we investigated whether VKORC1 -1173C>T, CYP2C9*2, and CYP2C9*3 gene polymorphisms are associated with warfarin dose adjustment and related bleeding events. METHODS This cross-sectional study was conducted on Saudi adults receiving warfarin for more than 1 month. Their demographics and relevant clinical data were obtained. Genotyping for VKORC1 -1173C>T, CYP2C9*2, and CYP2C9*2 genotypes was performed. RESULTS Patients who are homozygous for the mutant T allele VKORC1 T/T required the lowest warfarin daily maintenance dose, compared to VKORC1 C/T and VKORC1 C/C. Similarly, there was a significant reduction in warfarin daily maintenance dose among CYP2C9*1/*3 and CYP2C9*1/*2 groups compared to CYP2C9*1/*1. However, we found no significant correlation between the studied polymorphisms and warfarin-associated bleeding. CONCLUSIONS Similar to other populations, the VKORC1 and CYP2C9 gene polymorphisms are significantly associated with warfarin dosage in Saudi patients. The presence of at least one copy of the mutant alleles for VKORC1 -1173C>T, CYP2C9*2, and CYP2C9*3 is associated with a significant reduction in warfarin maintenance dose.
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Affiliation(s)
- Jasmine Holail
- Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Reem Mobarak
- Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Bandar Al-Ghamdi
- Heart Center, King Faisal Specialist Hospital and Research Center (KFSH&RC), Riyadh, Saudi Arabia
| | - Ahmad Aljada
- Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Hana Fakhoury
- Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
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Holail J, Mobarak R, Al-Ghamdi B, Aljada A, Fakhoury H. Association of VKORC1 and CYP2C9 single-nucleotide polymorphisms with warfarin dose adjustment in Saudi patients. Drug Metab Pers Ther 2022; 0:dmdi-2022-0108. [PMID: 35365981 DOI: 10.1515/dmdi-2022-0108] [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: 01/24/2022] [Accepted: 02/14/2022] [Indexed: 11/15/2022]
Abstract
OBJECTIVES Despite its wide usage, warfarin therapy remains challenging due to its narrow therapeutic index, inter-individual response variability, and risk of bleeding. Previous reports have suggested that polymorphisms in VKORC1 and CYP2C9 genes could influence warfarin therapy. Herein, we investigated whether VKORC1 -1173C>T, CYP2C9*2, and CYP2C9*3 gene polymorphisms are associated with warfarin dose adjustment and related bleeding events. METHODS This cross-sectional study was conducted on Saudi adults receiving warfarin for more than 1 month. Their demographics and relevant clinical data were obtained. Genotyping for VKORC1 -1173C>T, CYP2C9*2, and CYP2C9*2 genotypes was performed. RESULTS Patients who are homozygous for the mutant T allele VKORC1 T/T required the lowest warfarin daily maintenance dose, compared to VKORC1 C/T and VKORC1 C/C. Similarly, there was a significant reduction in warfarin daily maintenance dose among CYP2C9*1/*3 and CYP2C9*1/*2 groups compared to CYP2C9*1/*1. However, we found no significant correlation between the studied polymorphisms and warfarin-associated bleeding. CONCLUSIONS Similar to other populations, the VKORC1 and CYP2C9 gene polymorphisms are significantly associated with warfarin dosage in Saudi patients. The presence of at least one copy of the mutant alleles for VKORC1 -1173C>T, CYP2C9*2, and CYP2C9*3 is associated with a significant reduction in warfarin maintenance dose.
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Affiliation(s)
- Jasmine Holail
- Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Reem Mobarak
- Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Bandar Al-Ghamdi
- Heart Center, King Faisal Specialist Hospital and Research Center (KFSH&RC), Riyadh, Saudi Arabia
| | - Ahmad Aljada
- Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Hana Fakhoury
- Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
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Baban A, Iodice FG, Di Molfetta A, Cicenia M, Rizzo C, Agolini E, Drago F, Novelli A, Di Chiara L, Testa G, Amodeo A. Deciphering Genetic Variants of Warfarin Metabolism in Children With Ventricular Assist Devices. Pediatr Cardiol 2021; 42:1082-1087. [PMID: 33837838 DOI: 10.1007/s00246-021-02585-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 03/18/2021] [Indexed: 10/21/2022]
Abstract
Warfarin is prescribed in patients with ventricular assist devices (VADs). Dosage depends on several factors including the underlying genotype. These include polymorphisms of genes encoding cytochrome P450 enzymes, the main ones being CYP2C9, VKORC1, and CYP4F2. The objectives of this study were to evaluate the prevalence of CY2CP9 1*2*3*, VKORC1, and CYP4F2 in children with VADs and the time to reach the target international normalized ratio. We performed a retrospective/prospective study in children with VADs. We recorded polymorphisms, disease, type of VAD, ethnicity, age, gender, height, weight, INR values, bleeding, and thromboembolic episodes. Informed consent was obtained. We enrolled 34 children (19 male, 15 female), with a median age of 2 years (range 0.3-17 years) and median weight of 6.9Kg. The Berlin Heart was the most commonly implanted VAD (22/34; 64%), and the most common diagnosis was dilated cardiomyopathy. Statistical analysis confirmed a significant partial correlation with VKORC1 CC (p = 0.019). The CYP2C9*2 CT genotype showed a late rise in target INR values (p = 0.06), while the CYP2C9*2 CC showed a tendency toward an early INR rise (p = 0.024). We provide new information on the contribution of the warfarin polymorphisms in children with VAD implantation. Pharmacogenomic dosing for children using warfarin has the potential to improve clinical care in VAD patients. Patients with the CYP2C9*2 CT genotype may need more time or higher doses to reach target INR, while clinicians may need to be aware of the potential for a rapid rise in INR in patients with the CYP2C9*2 CC genotype.
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Affiliation(s)
- Anwar Baban
- The European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart - ERN GUARD-Heart. Pediatric Cardiology and Arrhythmia/Syncope Units, Bambino Gesù Children Hospital and Research Institute, Piazza Sant'Onofrio 4 - 00165, Rome, Italy.
| | - Francesca G Iodice
- Paediatric Cardiac Anesthesia and Intensive Care Unit, Bambino Gesu' Children Hospital, Rome, Italy
| | - Arianna Di Molfetta
- Heart Failure, Transplant and Mechanical Assistance Program Unit, Bambino Gesù Children Hospital, Rome, Italy
| | - Marianna Cicenia
- The European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart - ERN GUARD-Heart. Pediatric Cardiology and Arrhythmia/Syncope Units, Bambino Gesù Children Hospital and Research Institute, Piazza Sant'Onofrio 4 - 00165, Rome, Italy
| | - Caterina Rizzo
- Department of Infectious Diseases, Istituto Superiore Di Sanità, Rome, Italy
| | - Emanuele Agolini
- Genetics and Rare Diseases Research Division, Bambino Gesù Children Hospital, Rome, Italy
| | - Fabrizio Drago
- The European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart - ERN GUARD-Heart. Pediatric Cardiology and Arrhythmia/Syncope Units, Bambino Gesù Children Hospital and Research Institute, Piazza Sant'Onofrio 4 - 00165, Rome, Italy
| | - Antonio Novelli
- Genetics and Rare Diseases Research Division, Bambino Gesù Children Hospital, Rome, Italy
| | - Luca Di Chiara
- Paediatric Cardiac Anesthesia and Intensive Care Unit, Bambino Gesu' Children Hospital, Rome, Italy
| | - Giuseppina Testa
- Paediatric Cardiac Anesthesia and Intensive Care Unit, Bambino Gesu' Children Hospital, Rome, Italy
| | - Antonio Amodeo
- Heart Failure, Transplant and Mechanical Assistance Program Unit, Bambino Gesù Children Hospital, Rome, Italy
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Tamura R, Watanabe N, Nakamura S, Yoshimura N, Ozawa S, Hirono K, Ichida F, Taguchi M. Evaluation of the effects of ontogenetic or maturation functions and chronic heart failure on the model analysis for the dose-response relationship of warfarin in Japanese children. Eur J Clin Pharmacol 2019; 75:913-920. [PMID: 30848333 DOI: 10.1007/s00228-019-02652-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 02/15/2019] [Indexed: 01/29/2023]
Abstract
PURPOSE We previously demonstrated that the rational pediatric dosage of warfarin can be well-described by a SIZE parameter that includes an allometry exponent of weight. On the other hand, allometry alone is considered to be insufficient to predict drug clearance in neonates and infants. The primary purpose of the present study was to evaluate the effects of incorporation of the maturation process into the analysis model for the dose-response relationship of warfarin in Japanese children. In addition, we evaluated the effect of chronic heart failure (CHF) on the response to warfarin as an independent risk factor for increased anticoagulant effects. METHODS Thirty-eight patients with stable anticoagulation by warfarin were enrolled. During a mean follow-up period of 4.74 ± 3.51 years, 1092 data points including prothrombin time-international normalized ratio (PT-INR) were obtained. The data were subjected to multiple regression analysis to identify covariates related to the anticoagulant effects. RESULTS Two different models describing the maturation process did not improve the predictive performance for the dose-response relationship in pediatric patients. In addition to the SIZE-normalized daily dose, the vitamin K epoxide reductase complex 1 (VKORC1) genotype, and concomitant use of bosentan, CHF was identified as a covariate increasing the anticoagulant effects of warfarin to 118%. CONCLUSION The SIZE parameter was useful even without incorporation of maturation models to describe the response to warfarin in pediatric patients, and our longitudinal follow-up study design with multiple observations was beneficial to detect changes within individual subjects.
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Affiliation(s)
- Rika Tamura
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan
| | - Nao Watanabe
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan
| | - Saki Nakamura
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan
| | - Naoki Yoshimura
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan
| | - Sayaka Ozawa
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan
| | - Keiichi Hirono
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan
| | - Fukiko Ichida
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan
| | - Masato Taguchi
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan.
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Mizera L, Geisler T, Mörike K, Gawaz M, Steeg M. Problems in anticoagulation of a patient with antibiotic treatment for endocarditis: interaction of rifampicin and vitamin K antagonists. BMJ Case Rep 2018; 2018:bcr-2016-215155. [PMID: 29440136 DOI: 10.1136/bcr-2016-215155] [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] [Indexed: 11/03/2022] Open
Abstract
The cytochrome P450 is a superfamily of isoenzymes that are responsible for the metabolism of many drugs. Significant changes in pharmacokinetics and drug interactions may be due to induction of hepatic cytochrome P450 enzymes. Rifampicin is a common inducer of CYP3A4. We report a case of a 57-year-old woman who was suspected for endocarditis and therefore treated with rifampicin. Due to previous mechanical aortic valve replacement, she also received phenprocoumon for anticoagulation. Although continuing anticoagulant therapy, antibiotic coadministration led to normal international normalised ratio (INR) level. Fifteen days after the treatment with rifampicin ended, INR returned to therapeutic level.
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Affiliation(s)
- Lars Mizera
- Klinik für Kardiologie und Kreislauferkrankungen, Universitätsklinikum Tübingen, Tuebingen, Germany
| | - Tobias Geisler
- Klinik für Kardiologie und Kreislauferkrankungen, Universitätsklinikum Tübingen, Tuebingen, Germany
| | - Klaus Mörike
- Department fur Experimentelle und Klinische Pharmakologie und Toxikologie, Eberhard Karls Universitat Tubingen, Tübingen, Germany
| | - Meinrad Gawaz
- Klinik für Kardiologie und Kreislauferkrankungen, Universitätsklinikum Tübingen, Tuebingen, Germany
| | - Martin Steeg
- Klinik für Kardiologie und Kreislauferkrankungen, Universitätsklinikum Tübingen, Tuebingen, Germany
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Wakamiya T, Hokosaki T, Tsujimoto SI, Kadota K, Nakano Y, Watanabe S, Iwamoto M, Yanagimachi M, Ito S. Effect of VKORC1, CYP2C9, CFP4F2, and GGCX Gene Polymorphisms on Warfarin Dose in Japanese Pediatric Patients. Mol Diagn Ther 2017; 20:393-400. [PMID: 27262824 DOI: 10.1007/s40291-016-0212-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
BACKGROUND Warfarin dosage requirements show considerable inter-individual variability. There are some reports of warfarin dose regimens correlating with single nucleotide polymorphisms (SNP) for CYP2C9, VKORC1 and other genes in adults. In children, however, reports are scarcer than in adults and the number of genes examined is more limited. We explored the effects of genetic variation on warfarin dose requirement in Japanese pediatric patients. METHODS A total of 45 patients who were prescribed warfarin at the Yokohama City University Hospital were included in this study. The influence of genetic polymorphisms on stable warfarin dosage requirement was investigated by genotyping SNPs of the VKORC1, CYP2C9, CYP4F2, and GGCX genes (rs9923231, rs1057910, rs2108622, and rs699664, respectively) in each patient. RESULTS Patients with the TT genotype in rs9923231 in VKORC1 required significantly lower maintenance dosages than those with the TC genotype (p = 0.001). Multiple regression analysis showed that, while VKORC1 status and patient height account for 78.2 % of the variability in maintenance warfarin dosage, genetic polymorphisms in VKORC1 account for 27 %, although polymorphisms in CYP4F2 and GGCX had no effect on dosage and the effect of CYP2C9 could not be evaluated. CONCLUSIONS Polymorphisms in VKORC1 partially affected daily warfarin dosage requirements. VKORC1 genotype and height are the primary determinants influencing warfarin dosage in Japanese pediatric patients. Further studies with larger sample sizes are needed to confirm our results.
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Affiliation(s)
- Takuya Wakamiya
- Department of Pediatrics, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan
| | - Tatsunori Hokosaki
- Department of Pediatrics, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan
| | - Shin-Ichi Tsujimoto
- Department of Pediatrics, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan
| | - Keisuke Kadota
- Department of Pediatrics, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan
| | - Yusuke Nakano
- Department of Pediatrics, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan
| | - Shigeo Watanabe
- Department of Pediatrics, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan
| | - Mari Iwamoto
- Department of Pediatrics, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan
| | - Masakatsu Yanagimachi
- Department of Pediatrics, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan.
| | - Shuichi Ito
- Department of Pediatrics, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan
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Ang HX, Chan SL, Sani LL, Quah CB, Brunham LR, Tan BOP, Winther MD. Pharmacogenomics in Asia: a systematic review on current trends and novel discoveries. Pharmacogenomics 2017; 18:891-910. [DOI: 10.2217/pgs-2017-0009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
While early pharmacogenomic studies have primarily been carried out in Western populations, there has been a notable increase in the number of Asian studies over the past decade. We systematically reviewed all pharmacogenomic studies conducted in Asia published before 2016 to highlight trends and identify research gaps in Asia. We observed that pharmacogenomic research in Asia was dominated by larger developed countries, notably Japan and Korea, and mainly driven by local researchers. Studies were focused on drugs acting on the CNS, chemotherapeutics and anticoagulants. Significantly, several novel pharmacogenomic associations have emerged from Asian studies. These developments are highly encouraging for the strength of regional scientific and clinical community and propound the importance of discovery studies in different populations.
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Affiliation(s)
- Hazel Xiaohui Ang
- Genome Institute of Singapore, Agency for Science, Technology & Research, Singapore
| | - Sze Ling Chan
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology & Research, Singapore
| | - Levana L Sani
- Genome Institute of Singapore, Agency for Science, Technology & Research, Singapore
| | | | - Liam R Brunham
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology & Research, Singapore
- Department of Medicine, Centre for Heart Lung Innovation, University of British Columbia, Vancouver, BC, Canada
| | - Boon Ooi Patrick Tan
- Genome Institute of Singapore, Agency for Science, Technology & Research, Singapore
- Cancer Science Institute of Singapore, National University of Singapore, Singapore
- Cancer & Stem Cell Biology Program, Duke-NUS Graduate Medical School, Singapore
- Division of Cellular & Molecular Research, National Cancer Centre Singapore, Singapore
| | - Michael D Winther
- Genome Institute of Singapore, Agency for Science, Technology & Research, Singapore
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Nakamura S, Watanabe N, Yoshimura N, Ozawa S, Hirono K, Ichida F, Taguchi M. A model analysis for dose-response relationship of warfarin in Japanese children: An introduction of the SIZE parameter. Drug Metab Pharmacokinet 2016; 31:234-41. [PMID: 27234489 DOI: 10.1016/j.dmpk.2016.03.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 03/28/2016] [Accepted: 03/30/2016] [Indexed: 11/24/2022]
Abstract
The objective of the present study was to develop an optimal equation for the pediatric dose-response relationship of warfarin using a size parameter with an exponent of body weight (SIZE) which has been proposed for scaling drug clearance. Twenty patients with stable anticoagulation by warfarin were enrolled in the present study. During a mean follow-up period of 7.36 years, 857 data points were obtained. The average patient age and body weight were 8.49 years and 24.5 kg, respectively. The relative response index to warfarin with PT-INR values normalized by daily-dose per SIZE showed fewer systematic changes than those per body weight. The anticoagulant effect of warfarin in patients with the VKORC1 1173CT or 1173CC genotype was 47.3% of that with the 1173TT genotype. Concomitant use of bosentan attenuated the anticoagulant effect of warfarin to 84.1%. In conclusion, the SIZE parameter appeared to be an effective way to describe the pediatric dose-response relationship of warfarin, and consequently, a longitudinal follow-up study design with multiple measurements was useful to detect changes within individual subjects.
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Affiliation(s)
- Saki Nakamura
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan
| | - Nao Watanabe
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan
| | - Naoki Yoshimura
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan
| | - Sayaka Ozawa
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan
| | - Keiichi Hirono
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan
| | - Fukiko Ichida
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan
| | - Masato Taguchi
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan.
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Abstract
Given the rising incidence of thrombotic complications in paediatric patients, understanding of the pharmacologic behaviour of anticoagulant drugs in children has gained importance. Significant developmental differences between children and adults in the haemostatic system and pharmacologic parameters for individual drugs highlight potentially unique aspects of anticoagulant pharmacology in this special and vulnerable population. This review focuses on pharmacologic information relevant to the dosing of unfractionated heparin, low molecular weight heparin, warfarin, bivalirudin, argatroban and fondaparinux in paediatric patients. The bulk of clinical experience with paediatric anticoagulation rests with the first three of these agents, each of which requires higher bodyweight-based dosing for the youngest patients, compared with adults, in order to achieve comparable pharmacodynamic effects, likely related to an inverse correlation between age and bodyweight-normalized clearance of these drugs. Whether extrapolation of therapeutic ranges targeted for adult patients prescribed these agents is valid for children, however, is unknown and a high priority for future research. Novel oral anticoagulants, such as dabigatran, rivaroxaban and apixaban, hold promise for future use in paediatrics but require further pharmacologic study in infants, children and adolescents.
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10
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A new nested allele-specific multiplex polymerase chain reaction method for haplotyping of VKORC1 gene to predict warfarin sensitivity. BIOMED RESEARCH INTERNATIONAL 2014; 2014:316310. [PMID: 24790995 PMCID: PMC3985146 DOI: 10.1155/2014/316310] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Revised: 02/23/2014] [Accepted: 02/25/2014] [Indexed: 11/18/2022]
Abstract
The vitamin K epoxide reductase complex 1 gene (VKORC1) is commonly assessed to predict warfarin sensitivity. In this study, a new nested allele-specific multiplex polymerase chain reaction (PCR) method that can simultaneously identify single nucleotide polymorphisms (SNPs) at VKORC1 381, 861, 5808, and 9041 for haplotype analysis was developed and validated. Extracted DNA was amplified in the first PCR DNA, which was optimized by investigating the effects of varying the primer concentrations, annealing temperature, magnesium chloride concentration, enzyme concentration, and the amount of DNA template. The amplification products produced from the first round of PCR were used as templates for a second PCR amplification in which both mutant and wild-type primers were added in separate PCR tubes, followed by optimization in a similar manner. The final PCR products were resolved by agarose gel electrophoresis and further analysed by using a VKORC1 genealogic tree to infer patient haplotypes. Fifty patients were identified to have H1H1, one had H1H2, one had H1H7, 31 had either H1H7 or H1H9, one had H1H9, eight had H7H7, and one had H8H9 haplotypes. This is the first method that is able to infer VKORC1 haplotypes using only conventional PCR methods.
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Giglia TM, Massicotte MP, Tweddell JS, Barst RJ, Bauman M, Erickson CC, Feltes TF, Foster E, Hinoki K, Ichord RN, Kreutzer J, McCrindle BW, Newburger JW, Tabbutt S, Todd JL, Webb CL. Prevention and Treatment of Thrombosis in Pediatric and Congenital Heart Disease. Circulation 2013; 128:2622-703. [DOI: 10.1161/01.cir.0000436140.77832.7a] [Citation(s) in RCA: 202] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Abstract
The use of genetic information to guide medication decisions holds great promise to improve therapeutic outcomes through increased efficacy and reduced adverse events. As in many areas of medicine, pediatric research and clinical implementation in pharmacogenetics lag behind corresponding adult discovery and clinical applications. In adults, genotype-guided clinical decision support for medications such as clopidogrel, warfarin and simvastatin are in use in some medical centers. However, research conducted in pediatric populations demonstrates that the models and practices developed in adults may be inaccurate in children, and some applications lack any pediatric research to guide clinical decisions. To account for additional factors introduced by developmental considerations in pediatric populations and provide pediatric patients with maximal benefit from genotype-guided therapy, the field will need to develop and employ creative solutions. In this article, we detail some concerns about research and clinical implementation of pharmacogenetics in pediatrics, and present potential mechanisms for addressing them.
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Affiliation(s)
- Sara L Van Driest
- Department of Pediatrics, Vanderbilt University, 2200 Children's Way, Nashville, TN 37232, USA ; The Monroe Carell Jr Children's Hospital at Vanderbilt, 8232 DOT, 2200 Children's Way, Nashville, TN 37232, USA
| | - Tracy L McGregor
- Department of Pediatrics, Vanderbilt University, 2200 Children's Way, Nashville, TN 37232, USA ; The Monroe Carell Jr Children's Hospital at Vanderbilt, 8232 DOT, 2200 Children's Way, Nashville, TN 37232, USA ; The Center for Human Genetics Research, 519 Light Hall, 2215 Garland Avenue, Nashville, TN 37232-0700, USA
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13
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Abstract
The use of genetic information to guide medication decisions holds great promise to improve therapeutic outcomes through increased efficacy and reduced adverse events. As in many areas of medicine, pediatric research and clinical implementation in pharmacogenetics lag behind corresponding adult discovery and clinical applications. In adults, genotype-guided clinical decision support for medications such as clopidogrel, warfarin and simvastatin are in use in some medical centers. However, research conducted in pediatric populations demonstrates that the models and practices developed in adults may be inaccurate in children, and some applications lack any pediatric research to guide clinical decisions. To account for additional factors introduced by developmental considerations in pediatric populations and provide pediatric patients with maximal benefit from genotype-guided therapy, the field will need to develop and employ creative solutions. In this article, we detail some concerns about research and clinical implementation of pharmacogenetics in pediatrics, and present potential mechanisms for addressing them.
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Affiliation(s)
- Sara L Van Driest
- Department of Pediatrics, Vanderbilt University, 2200 Children’s Way, Nashville, TN 37232, USA
- The Monroe Carell Jr Children’s Hospital at Vanderbilt, 8232 DOT, 2200 Children’s Way, Nashville, TN 37232, USA
| | - Tracy L McGregor
- Department of Pediatrics, Vanderbilt University, 2200 Children’s Way, Nashville, TN 37232, USA
- The Monroe Carell Jr Children’s Hospital at Vanderbilt, 8232 DOT, 2200 Children’s Way, Nashville, TN 37232, USA
- The Center for Human Genetics Research, 519 Light Hall, 2215 Garland Avenue, Nashville, TN 37232-0700, USA
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14
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Kumar DK, Shewade DG, Surendiran A, Adithan C. Genetic variation and haplotype structure of the gene Vitamin K epoxide reductase complex, subunit 1 in the Tamilian population. J Pharmacol Pharmacother 2013; 4:53-8. [PMID: 23662025 PMCID: PMC3643344 DOI: 10.4103/0976-500x.107683] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVE To study the genetic variation and haplotype structure of Vitamin K epoxide reductase complex, subunit 1 (VKORC1) gene in the Tamilian population. MATERIALS AND METHODS The study was performed on 210 unrelated, healthy volunteers of the Tamilian population, of either sex between the age group of 18-60 years. Five ml of venous blood sample was collected using sodium ethylene diamine tetra acetic acid (EDTA) as anticoagulant. DNA was extracted using phenol-chloroform extraction method. Eight single nucleotide polymorphisms (SNPs) VKORC1 rs9923231 (G), rs7196161 (T), rs2884737 (T), rs17708472 (C), rs9934438 (C), rs8050894 (G), rs23596121 (C), and rs7294 (A) were studied using real-time quantitative Polymerase Chain Reaction (qPCR) method and they were included for constructing five-major haplotype blocks of VKORC1 gene. RESULTS The major alleles of VKORC1 rs9923231 (G), rs7196161 (T), rs2884737 (T), rs17708472 (C), rs9934438 (C), rs8050894 (G), and rs23596121 (C), were found to be at frequencies of 90.0%, 89.2%, 90.9%, 94.1%, 90.7%, 89.5% and 91.2%, respectively. The variant allele of VKORC1 rs7294 (A) was more frequent (83.6%) in the Tamilian population. The frequencies of haplotypes HAP1 (GTTCCGCA), HAP2 (ACGCTCTG), HAP3 (GTTTCGCG), HAP4 (GTTCCGCG) and HAP5 (GCTCCCCG) were found to be 80.0%, 7.4%, 4.7%, 1.5% and 1.1%, respectively. CONCLUSION In the present study the allele- frequency distributions, genotype and haplotype frequencies of the VKORC1 gene was considered. The findings of this study provide the genetic information required for learning the association of VKORC1 genetic variation and oral anticoagulant dose variability among patients receiving oral anticoagulants in the Tamilian population.
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Affiliation(s)
- Dhakchinamoorthi Krishna Kumar
- Department of Pharmacology, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Pondicherry, India
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Jorgensen AL, FitzGerald RJ, Oyee J, Pirmohamed M, Williamson PR. Influence of CYP2C9 and VKORC1 on patient response to warfarin: a systematic review and meta-analysis. PLoS One 2012; 7:e44064. [PMID: 22952875 PMCID: PMC3430615 DOI: 10.1371/journal.pone.0044064] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 07/30/2012] [Indexed: 01/13/2023] Open
Abstract
Background Warfarin is a highly effective anticoagulant however its effectiveness relies on maintaining INR in therapeutic range. Finding the correct dose is difficult due to large inter-individual variability. Two genes, CYP2C9 and VKORC1, have been associated with this variability, leading to genotype-guided dosing tables in warfarin labeling. Nonetheless, it remains unclear how genotypic information should be used in practice. Navigating the literature to determine how genotype will influence warfarin response in a particular patient is difficult, due to significant variation in patient ethnicity, outcomes investigated, study design, and methodological rigor. Our systematic review was conducted to enable fair and accurate interpretation of which variants affect which outcomes, in which patients, and to what extent. Methodology/Principal Findings A comprehensive search strategy was applied and 117 studies included. Primary outcomes were stable dose, time to stable dose and bleeding events. Methodological quality was assessed using criteria of Jorgensen and Williamson and data synthesized in meta-analyses using advanced methods. Pooled effect estimates were significant in most ethnic groups for CYP2C9*3 and stable dose (mutant types requiring between 1.1(0.7–1.5) and 2.3 (1.6–3.0)mg/day). Effect estimates were also significant for VKORC1 and stable dose for most ethnicities, although direction differed between asians and non-asians (mutant types requiring between 0.8(0.4–1.3) and 1.5(1.1–1.8)mg/day more in asians and between 1.5(0.7–2.2) and 3.1(2.7–3.6)mg/day less in non-asians). Several studies were excluded due to inadequate data reporting. Assessing study quality highlighted significant variability in methodological rigor. Notably, there was significant evidence of selective reporting, of outcomes and analysis approaches. Conclusions/Significance Genetic associations with warfarin response vary between ethnicities. In order to achieve unbiased estimates in different populations, a high level of methodological rigor must be maintained and studies should report sufficient data to enable inclusion in meta-analyses. We propose minimum reporting requirements, suggest methodological guidelines and provide recommendations for reducing the risk of selective reporting.
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Affiliation(s)
- Andrea L Jorgensen
- Department of Biostatistics, Shelley's Cottage, University of Liverpool, Liverpool, United Kingdom.
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Hirai K, Hayashi H, Ono Y, Izumiya K, Tanaka M, Suzuki T, Sakamoto T, Itoh K. Influence of CYP4F2 polymorphisms and plasma vitamin K levels on warfarin sensitivity in Japanese pediatric patients. Drug Metab Pharmacokinet 2012; 28:132-7. [PMID: 22892446 DOI: 10.2133/dmpk.dmpk-12-rg-078] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The aim of this study was to reveal the contribution of CYP4F2, CYP2C9, and VKORC1 genetic polymorphisms on the pharmacokinetics and pharmacodynamics of warfarin in Japanese pediatric patients. Genetic analyses of CYP4F2 (rs2108622), CYP2C9 (*2 and *3), and VKORC1 (-1639G>A) were performed, and plasma unbound warfarin, vitamin K1 (VK1), and menaquinone-4 (MK-4) concentrations were determined in 37 Japanese pediatric patients. The patients with CYP4F2 variant alleles C/T and T/T scored significantly lower values for the warfarin sensitivity index (INR/Cpss) and had significantly higher plasma concentrations of MK-4 than patients with the CYP4F2 allele C/C. Moreover, the plasma MK-4 concentration was negatively correlated with the warfarin sensitivity index. In contrast, the VKORC1 genetic polymorphism did not influence the warfarin sensitivity index. In patients with the CYP2C9 *3 allele, the unbound oral clearance values (normalized to body surface area) for S-warfarin were found to be significantly lower than in patients with the wild-type allele. In conclusion, CYP4F2 genetic polymorphism and plasma MK-4 concentration influence the pharmacodynamics of warfarin, suggesting a mechanism though which CYP4F2 genotype affects warfarin dose.
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Affiliation(s)
- Keita Hirai
- Department of Clinical Pharmacology & Genetics, School of Pharmaceutical Sciences, University of Shizuoka, and Department of Pharmacy, Shizuoka Children's Hospital, Shizuoka, Japan
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Giansante C, Fiotti N, Altamura N, Pitacco P, Consoloni L, Scardi S, Mazzone C, Grassi G, Pandullo C, Di Lenarda A. Oral anticoagulation and VKORC1 polymorphism in patients with a mechanical heart prosthesis: a 6-year follow-up. J Thromb Thrombolysis 2012; 34:506-12. [DOI: 10.1007/s11239-012-0740-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Vitamin K antagonists in children with heart disease: height and VKORC1 genotype are the main determinants of the warfarin dose requirement. Blood 2011; 119:861-7. [PMID: 22130800 DOI: 10.1182/blood-2011-07-365502] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Managing vitamin K antagonist (VKA) therapy is challenging in children because of a narrow therapeutic range and wide inter- and intra-individual variability in dose response. Only a few small studies have investigated the effect of nongenetic and genetic factors on the dose response to VKAs in children. In a cohort study including 118 children (median age 9 years; range, 3 months-18 years) mostly with cardiac disease, we evaluated by multivariate analysis the relative contribution of nongenetic factors and VKORC1/CYP2C9/CYP4F2 genotypes on warfarin (n = 83) or fluindione (n = 35) maintenance dose and the influence of these factors on the time spent within/above/below the range. The results showed that height, target international normalized ratio and VKORC1 and CYP2C9 genotypes were the main determinants of warfarin dose requirement, accounting for 48.1%, 4.4%, 18.2%, and 2.0% of variability, respectively, and explaining 69.7% of the variability. Our model predicted the warfarin dose within 7 mg/wk in 86.7% of patients. None of the covariates was associated with the time spent above or below the international normalized ratio range. Whether this model predicts accurately the effective maintenance dose is currently being investigated.
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Jorgensen AL, Pirmohamed M. Risk modeling strategies for pharmacogenetic studies. Pharmacogenomics 2011; 12:397-410. [DOI: 10.2217/pgs.10.198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Pharmacogenetic risk models offer great promise as treatment decision tools; however, their uptake in routine clinical practice is so far disappointing, not least due to the lack of evidence of their benefit in randomized controlled trials and other types of studies. Prior to conducting such a study, it is imperative that the model’s predictive capability is first of all proven, and that it is shown to be superior to the most appropriate alternative model. When demonstrating predictive capability, clinical implications of applying the model should be a key consideration, and the Decision Curve Analysis method takes this into account for binary outcomes. Furthermore, when comparing a novel model to the best alternative, methods such as Net Reclassification Improvement or Integrated Discrimination Difference are recommended as they provide a more reliable comparison than other methods currently in common use. Where outcome is continuous, such as therapeutic dose, assessing a model’s performance is generally more intuitive and straightforward since the aim is to achieve a predicted dose as close as possible to the true therapeutic dose.
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Affiliation(s)
- Andrea L Jorgensen
- Department of Biostatistics, University of Liverpool, Shelley’s Cottage, Brownlow Street, Liverpool, L69 3GS, UK
| | - Munir Pirmohamed
- The Wolfson Centre for Personalised Medicine, Department of Pharmacology, University of Liverpool, Waterhouse Buildings, 1–5 Brownlow Street, Liverpool, L69 3GL, UK
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Mahajan P, Meyer KS, Wall GC, Price HJ. Clinical applications of pharmacogenomics guided warfarin dosing. Int J Clin Pharm 2011; 33:10-9. [PMID: 21365388 DOI: 10.1007/s11096-011-9486-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Accepted: 10/11/2010] [Indexed: 12/26/2022]
Abstract
AIM OF THE REVIEW To assess the state of the literature concerning pharmacogenomic testing in patients requiring vitamin K antagonists, specifically warfarin. METHOD We conducted a literature search of MEDLINE and International Pharmaceutical Abstracts using the following words: warfarin, pharmacogenetic, and pharmacogenomic. The search results were reviewed by the authors and papers concerning pharmacogenomic testing in warfarin dosing were procured and reviewed. Additionally bibliographies of papers procured were also examined for other studies. The authors focused on clinical trials concerning the use of pharmacogenomic testing in warfarin dosing. RESULTS Although numerous studies have demonstrated that a significant portion of warfarin dosing variability can be explained by genetic polymorphisms, few prospective studies have been conducted that examine the integration of this information in practical dosing situations. Those that have, have shown that using pharmacogenomic information improves initial dosing estimates and decreases the need for frequent clinic visits and laboratory testing. Data showing a reduction in serious bleeding events is sparse. Cost-effectiveness analyses have generally shown a small but positive effect with pharmacogenomic testing in patients receiving warfarin. CONCLUSION Several studies have shown that pharmacogenomic testing for warfarin dosing is more accurate that other dosing schemes. Pharmacogenomic testing improves time to a therapeutic international normalized ratio while requiring fewer dosing adjustments. Patients who require higher or lower than usual doses seem to benefit the most. The cost-effectiveness of pharmacogenomic testing as well as preventing of outcomes such as bleeding or thrombosis are not yet elucidated. Pharmacists, especially those in a community setting can play a role in this new technology by educating prescribers and patients concerning pharmacogenomic testing, and by developing and using dosing protocols that incorporate its use.
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Affiliation(s)
- Pramod Mahajan
- College of Pharmacy and Health Sciences, Drake University, 2507 University Ave, Des Moines, IA 50310, USA
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Kato Y, Ichida F, Saito K, Watanabe K, Hirono K, Miyawaki T, Yoshimura N, Horiuchi I, Taguchi M, Hashimoto Y. Effect of the VKORC1 genotype on warfarin dose requirements in Japanese pediatric patients. Drug Metab Pharmacokinet 2011; 26:295-9. [PMID: 21273734 DOI: 10.2133/dmpk.dmpk-10-nt-082] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The primary aim of the present study was to evaluate the effect of the genotype of vitamin K epoxide reductase complex 1 (VKORC1) on warfarin dose requirements in Japanese pediatric patients. Forty-eight pediatric patients (0.42-19.25 years old) in whom stable anticoagulation was achieved by warfarin were enrolled in this study, and the polymorphic alleles of VKORC1 and CYP2C9 were determined for each subject. The relative impact of covariates on the anticoagulant effect of warfarin was evaluated by multiple regression analysis. It was found that VKORC1 genotype and age were major factors affecting the relationship between the weight-normalized warfarin dose and the therapeutic prothrombin time-international normalized ratio (PT-INR). Because only one patient had the CYP2C9*3 allele, we could not evaluate the effect of CYP2C9 polymorphisms on the anticoagulant effect of warfarin. In contrast, the anticoagulant effect of warfarin in patients with the VKORC1 1173CT or 1173CC genotype was 52.3% of that in patients with the 1173TT genotype. In addition, the anticoagulant effect of warfarin was shown to increase by 10.5% per year in Japanese pediatric patients. In conclusion, genotyping of VKORC1 will be useful in establishing individual anticoagulant therapy with warfarin, and it should be noted that a higher weight-normalized dose of warfarin is required in younger pediatric patients.
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Affiliation(s)
- Yuya Kato
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan
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Mahajan P, Meyer KS, Wall GC, Price HJ. Clinical applications of pharmacogenomics guided warfarin dosing. Int J Clin Pharm 2010; 35:359-68. [DOI: 10.1007/s11096-010-9448-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Accepted: 10/11/2010] [Indexed: 12/28/2022]
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Abstract
With the US Food and Drug Administration's recent label change of warfarin to include genetic testing for warfarin sensitivity, manufacturers are developing assays, and laboratories are offering testing. This article describes the genetic variants for which testing is available. Current technologies and assays are compared, including considerations for laboratories in choosing a method. Finally, laboratory issues that apply to all methods, such as quality control and proficiency testing as well as service issues including turn-around-time requirements are discussed.
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Affiliation(s)
- Elaine Lyon
- Department of Pathology, University of Utah, Salt Lake City, Utah, USA.
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Schelleman H, Limdi NA, Kimmel SE. Ethnic differences in warfarin maintenance dose requirement and its relationship with genetics. Pharmacogenomics 2009; 9:1331-46. [PMID: 18781859 DOI: 10.2217/14622416.9.9.1331] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Warfarin is a highly efficacious drug, but management of warfarin is difficult, in part because of the large interindividual maintenance dose differences. Warfarin dose requirements differ by race and it has been suggested that some of these differences are owing to genetic diversity. For example, persons of African descent have lower allele frequencies of the CYP2C9*2 and *3 and VKORC1 1173T allele, which have been associated with lower warfarin dose requirements in Caucasians. Since there is currently debate whether genetic information should be used in clinical practice to determine the starting dose for a warfarin initiator, it is of great importance to determine whether everyone will benefit from this knowledge.
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Affiliation(s)
- Hedi Schelleman
- Center for Clinical Epidemiology and Biostatistics, and Department of Biostatistics & Epidemiology, University of Pennsylvania School of Medicine, 826 Blockley Hall, 423 Guardian Drive, Philadelphia, PA 19104-6021, USA.
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Abstract
Significant interest in the pharmacogenetics of warfarin therapy has been triggered with the recent package insert update that highlights the potential role of pharmacogenetics in improving the safety and effectiveness of warfarin. We review the evidence of the influence of the two key genes of interest, the cytochrome P450 2C9 gene, CYP2C9, and the vitamin K epoxide reductase complex 1 gene, VKORC1, on warfarin response and discuss the implications of current knowledge for clinical practice. The influence of CYP2C9 and VKORC1 genotypes on warfarin dose requirements has been consistently demonstrated in diverse racial and ethnic patient groups in observational studies and randomized clinical trials. Dosing algorithms have been developed that incorporate clinical, demographic, and genetic information to help select a warfarin starting dose. Furthermore, CYP2C9 variant genotypes have been associated with a significantly increased risk of serious bleeding events. However, evidence to date from prospective, controlled studies has not demonstrated an added benefit of incorporating genotype-guided therapy in improving anticoagulation control or in preventing or reducing the risk of hemorrhagic or thromboembolic complications. Research efforts designed to evaluate the effectiveness of genotype-guided therapy in improving outcomes are under way. However, the routine use of CYP2C9 and VKORC1 genotyping in the general patient population who begin warfarin therapy is not supported by evidence currently available.
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Affiliation(s)
- Nita A Limdi
- Department of Neurology, University of Alabama, Birmingham, Alabama 35294-0021, USA.
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Salvati EA, Sharrock NE, Westrich G, Potter HG, Valle AGD, Sculco TP. The 2007 ABJS Nicolas Andry Award: three decades of clinical, basic, and applied research on thromboembolic disease after THA: rationale and clinical results of a multimodal prophylaxis protocol. Clin Orthop Relat Res 2007; 459:246-54. [PMID: 17545765 DOI: 10.1097/blo.0b013e31805b7681] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Total hip arthroplasty is an operation with a high risk for venous thromboembolism. Three decades of research conducted at the Hospital for Special Surgery identified the exact timing of the thrombogenic stimulus during surgery, defined the role of magnetic resonance venography, and established the role of certain genetic and acquired predispositions. Based on these studies, we implemented a multimodal prophylaxis consisting of a series of safe preventive measures applied before, during, and immediately after surgery to reduce the risk of venous thromboembolism. If these safe preventive measures are strictly observed, postoperative pharmacologic prophylaxis does not need to be aggressive in the patient without predisposing factors who mobilizes promptly, thus diminishing the risk of bleeding associated with the use of anticoagulants and the overall cost of care. Our clinical experience with more than 5000 total hip arthroplasties performed during the last decade and closely followed prospectively for a minimum of 3 months clearly shows this multimodal prophylaxis is safe and effective resulting in a very low prevalence of thromboembolism.
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Affiliation(s)
- Eduardo A Salvati
- Department of Orthopaedics, Hospital for Special Surgery and Weill Medical College of Cornell University, New York, NY 10021, USA.
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