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Muflih S, Alshogran OY, Al-Azzam S, Al-Taani G, Khader YS. Physicians' Knowledge and Attitudes Regarding Point-of-Care Pharmacogenetic Testing: A Hospital-Based Cross-Sectional Study. PHARMACOGENOMICS & PERSONALIZED MEDICINE 2021; 14:655-665. [PMID: 34103970 PMCID: PMC8179816 DOI: 10.2147/pgpm.s307694] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 04/26/2021] [Indexed: 12/03/2022]
Abstract
Introduction Pharmacogenetic testing (PGx) is a diagnostic technique used by physicians to determine the possible reactions of patients to drug treatment on the basis of their genetic makeup. The aim of this study was to determine the impact of physicians’ awareness, attitudes, and sociodemographics on the adoption of point-of-care (POC) PGx testing as a diagnostic method, as well as the impact of their knowledge, attitudes, and sociodemographics on its adoption. Methods A cross-sectional survey of 200 physicians and medical trainees working at the Clinics of King Abdullah University Hospital in Jordan was performed. Data on sociodemographics, knowledge and attitudes concerning PGx testing, genetic information sources, and barriers to POC-PGx testing adoption were gathered. Results Participants’ perceived knowledge of the role of PGx testing in therapeutic decision-making was rated as “Excellent” (1.9%), “Very Good” (19.4%), “Good” (34.4%), “Fair” (32.5%), and “Poor” (11.9%). Physicians’ actual knowledge of PGx testing was adequate (mean=3.56 out of 7, SD=1.2), but their attitudes were generally favorable (mean=3.64 out of 5.00, SD=0.52). According to Rogers’ theory, many variables (eg, perceived need, relative advantage, compatibility) had a significant impact on physicians’ willingness to endorse POC-PGx testing. Discussion The majority of physicians stated that they were unaware of PGx testing. Physicians’ perceived knowledge of POC-PGx testing, however, was higher than those who participated in other studies. Participants were optimistic about the future benefits of PGx testing in prescribing effective medications and reducing potential side effects, which were consistent with previous studies. Physicians’ willingness to accept and implement POC-PGx testing was hampered by a lack of PGx expertise, as well as concerns about patient confidentiality, employability, and insurability. More training and genetic courses are needed, according to the majority of participants.
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Affiliation(s)
- Suhaib Muflih
- Department of Clinical Pharmacy, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Osama Y Alshogran
- Department of Clinical Pharmacy, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Sayer Al-Azzam
- Department of Clinical Pharmacy, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Ghaith Al-Taani
- Department of Pharmacy Practice, Yarmouk University, Irbid, Jordan
| | - Yousef S Khader
- Department of Public Health, Jordan University of Science and Technology, Irbid, 22110, Jordan
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2
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Advances in Directly Amplifying Nucleic Acids from Complex Samples. BIOSENSORS-BASEL 2019; 9:bios9040117. [PMID: 31574959 PMCID: PMC6955841 DOI: 10.3390/bios9040117] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 09/23/2019] [Accepted: 09/26/2019] [Indexed: 12/15/2022]
Abstract
Advances in nucleic acid amplification technologies have revolutionized diagnostics for systemic, inherited, and infectious diseases. Current assays and platforms, however, often require lengthy experimental procedures and multiple instruments to remove contaminants and inhibitors from clinically-relevant, complex samples. This requirement of sample preparation has been a bottleneck for using nucleic acid amplification tests (NAATs) at the point of care (POC), though advances in “lab-on-chip” platforms that integrate sample preparation and NAATs have made great strides in this space. Alternatively, direct NAATs—techniques that minimize or even bypass sample preparation—present promising strategies for developing POC diagnostic tools for analyzing real-world samples. In this review, we discuss the current status of direct NAATs. Specifically, we surveyed potential testing systems published from 1989 to 2017, and analyzed their performances in terms of robustness, sensitivity, clinical relevance, and suitability for POC diagnostics. We introduce bubble plots to facilitate our analysis, as bubble plots enable effective visualization of the performances of these direct NAATs. Through our review, we hope to initiate an in-depth examination of direct NAATs and their potential for realizing POC diagnostics, and ultimately transformative technologies that can further enhance healthcare.
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Popov Aleksandrov A, Mirkov I, Ninkov M, Mileusnic D, Demenesku J, Subota V, Kataranovski D, Kataranovski M. Effects of warfarin on biological processes other than haemostasis: A review. Food Chem Toxicol 2018; 113:19-32. [PMID: 29353071 DOI: 10.1016/j.fct.2018.01.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 11/29/2017] [Accepted: 01/12/2018] [Indexed: 02/07/2023]
Abstract
Warfarin is the world's most widely used anticoagulant drug. Its anticoagulant activity is based on the inhibition of the vitamin K-dependent (VKD) step in the complete synthesis of a number of blood coagulation factors that are required for normal blood coagulation. Warfarin also affects synthesis of VKD proteins not related to haemostasis including those involved in bone growth and vascular calcification. Antithrombotic activity of warfarin is considered responsible for some aspects of its anti-tumour activity of warfarin. Some aspects of activities against tumours seem not to be related to haemostasis and included effects of warfarin on non-haemostatic VKD proteins as well as those not related to VKD proteins. Inflammatory/immunomodulatory effects of warfarin indicate much broader potential of action of this drug both in physiological and pathological processes. This review provides an overview of the published data dealing with the effects of warfarin on biological processes other than haemostasis.
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Affiliation(s)
- Aleksandra Popov Aleksandrov
- Immunotoxicology Group, Department of Ecology, Institute for Biological Research "Sinisa Stankovic", University of Belgrade, 142 Bulevar Despota Stefana, 11000 Belgrade, Serbia
| | - Ivana Mirkov
- Immunotoxicology Group, Department of Ecology, Institute for Biological Research "Sinisa Stankovic", University of Belgrade, 142 Bulevar Despota Stefana, 11000 Belgrade, Serbia
| | - Marina Ninkov
- Immunotoxicology Group, Department of Ecology, Institute for Biological Research "Sinisa Stankovic", University of Belgrade, 142 Bulevar Despota Stefana, 11000 Belgrade, Serbia
| | - Dina Mileusnic
- Immunotoxicology Group, Department of Ecology, Institute for Biological Research "Sinisa Stankovic", University of Belgrade, 142 Bulevar Despota Stefana, 11000 Belgrade, Serbia
| | - Jelena Demenesku
- Immunotoxicology Group, Department of Ecology, Institute for Biological Research "Sinisa Stankovic", University of Belgrade, 142 Bulevar Despota Stefana, 11000 Belgrade, Serbia
| | - Vesna Subota
- Institute for Medical Biochemistry, Military Medical Academy, 17 Crnotravska, 11000 Belgrade, Serbia
| | - Dragan Kataranovski
- Immunotoxicology Group, Department of Ecology, Institute for Biological Research "Sinisa Stankovic", University of Belgrade, 142 Bulevar Despota Stefana, 11000 Belgrade, Serbia; Institute of Zoology, Faculty of Biology, University of Belgrade, 16 Studentski trg, 11000 Belgrade, Serbia
| | - Milena Kataranovski
- Immunotoxicology Group, Department of Ecology, Institute for Biological Research "Sinisa Stankovic", University of Belgrade, 142 Bulevar Despota Stefana, 11000 Belgrade, Serbia; Institute of Physiology and Biochemistry, Faculty of Biology, University of Belgrade, 16 Studentski trg, 11000 Belgrade, Serbia.
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4
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Ragia G, Karantza IM, Kelli-Kota E, Kolovou V, Kolovou G, Konstantinides S, Maltezos E, Tavridou A, Tziakas D, Maitland-van der Zee AH, Manolopoulos VG. Role of CYP4F2, CYP2C19, and CYP1A2 polymorphisms on acenocoumarol pharmacogenomic algorithm accuracy improvement in the Greek population: need for sub-phenotype analysis. Drug Metab Pers Ther 2017; 32:183-190. [PMID: 29252193 DOI: 10.1515/dmpt-2017-0034] [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: 11/07/2017] [Accepted: 11/15/2017] [Indexed: 11/15/2022]
Abstract
BACKGROUND We have earlier developed a pharmacogenomic algorithm for acenocoumarol dose prediction in Greek patients that included CYP2C9/VKORC1 genetic information. This study aims at analyzing the potential effect of CYP4F2, CYP2C19, and CYP1A2 gene polymorphisms on acenocoumarol dose requirements and at further improving the Greek-specific pharmacogenomic algorithm. METHODS A total of 205 Greek patients taking acenocoumarol (140 who reached and 65 who did not reach stable dose), participants of acenocoumarol EU-PACT trial, were included in the study. CYP4F2, CYP2C19, and CYP1A2 polymorphisms were genotyped by use of the PCR-RFLP method. All patients were previously genotyped for CYP2C9/VKORC1 polymorphisms. RESULTS In the pooled sample, CYP4F2, CYP2C19, and CYP1A2 polymorphisms do not affect independently acenocoumarol dose requirements. For CYP4F2, significant effects were found on patients' ability to reach stable dose and on acenocoumarol dose requirements when CYP2C9/VKORC1 sub-phenotypes were analyzed. Specifically, when the patients were stratified according to their CYP2C9/VKORC1 functional bins, in sensitive responders, CYP4F2*3 allele carriers (CYP4F2 *1/*3 and *3/*3 genotypes) were more frequent in the patient group who reached stable dose (p=0.049). Additionally, in CYP2C9 intermediate metabolizers (IMs), after adjusting for age, weight, and VKORC1 genotypes, CYP4F2 genotypes were significantly associated with acenocoumarol stable dose (β: 0.07; 95% CI: 0.006-0.134; p=0.033). CONCLUSIONS CYP4F2 gene shows a prominent weak association with acenocoumarol dose requirements. Sub-phenotype analysis is potentially important in determining additional gene polymorphisms that are associated with acenocoumarol dose requirements.
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Affiliation(s)
- Georgia Ragia
- Laboratory of Pharmacology, Medical School, Democritus University of Thrace, Dragana Campus, 68100 Alexandroupolis, Greece, Phone: +30 2551 030523, Fax: +30 2551 030523; and DNALEX S.A., Alexandroupolis, Greece
| | - Ioanna-Maria Karantza
- Laboratory of Pharmacology, Medical School, Democritus University of Thrace, Alexandroupolis, Greece
| | - Eleni Kelli-Kota
- Laboratory of Pharmacology, Medical School, Democritus University of Thrace, Alexandroupolis, Greece
| | - Vana Kolovou
- Cardiology Department, Onassis Cardiac Surgery Center, Athens, Greece
| | - Genovefa Kolovou
- Cardiology Department, Onassis Cardiac Surgery Center, Athens, Greece
| | - Stavros Konstantinides
- University Cardiology Department, Medical School, Democritus University of Thrace, Alexandroupolis, Greece
| | - Efstratios Maltezos
- Second Department of Internal Medicine, Democritus University of Thrace, Alexandroupolis, Greece
| | - Anna Tavridou
- Laboratory of Pharmacology, Medical School, Democritus University of Thrace, Alexandroupolis, Greece
| | - Dimitrios Tziakas
- University Cardiology Department, Medical School, Democritus University of Thrace, Alexandroupolis, Greece
| | - Anke H Maitland-van der Zee
- Department of Pharmaceutical Sciences, Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht University, Utrecht, The Netherlands
| | - Vangelis G Manolopoulos
- Laboratory of Pharmacology, Medical School, Democritus University of Thrace, Alexandroupolis, Greece
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Al-Metwali B, Mulla H. Personalised dosing of medicines for children. J Pharm Pharmacol 2017; 69:514-524. [DOI: 10.1111/jphp.12709] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 01/12/2017] [Indexed: 12/16/2022]
Abstract
Abstract
Objectives
Doses for most drugs are determined from population-level information, resulting in a standard ?one-size-fits-all’ dose range for all individuals. This review explores how doses can be personalised through the use of the individuals’ pharmacokinetic (PK)-pharmacodynamic (PD) profile, its particular application in children, and therapy areas where such approaches have made inroads.
Key findings
The Bayesian forecasting approach, based on population PK/PD models that account for variability in exposure and response, is a potent method for personalising drug therapy. Its potential utility is even greater in young children where additional sources of variability are observed such as maturation of eliminating enzymes and organs. The benefits of personalised dosing are most easily demonstrated for drugs with narrow therapeutic ranges such as antibiotics and cytotoxics and limited studies have shown improved outcomes. However, for a variety of reasons the approach has struggled to make more widespread impact at the bedside: complex dosing algorithms, high level of technical skills required, lack of randomised controlled clinical trials and the need for regulatory approval.
Summary
Personalised dosing will be a necessary corollary of the new precision medicine initiative. However, it faces a number of challenges that need to be overcome before such an approach to dosing in children becomes the norm.
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Affiliation(s)
- Basma Al-Metwali
- School of Pharmacy, De Montfort University, Leicester, UK
- Department of Pharmacy, Glenfield Hospital, University Hospitals of Leicester, Leicester, UK
| | - Hussain Mulla
- Department of Pharmacy, Glenfield Hospital, University Hospitals of Leicester, Leicester, UK
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Ragia G, Kolovou V, Kolovou G, Konstantinides S, Maltezos E, Tavridou A, Tziakas D, Maitland-van der Zee AH, Manolopoulos VG. A novel acenocoumarol pharmacogenomic dosing algorithm for the Greek population of EU-PACT trial. Pharmacogenomics 2017; 18:23-34. [DOI: 10.2217/pgs-2016-0126] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aim: To generate and validate a pharmacogenomic-guided (PG) dosing algorithm for acenocoumarol in the Greek population. To compare its performance with other PG algorithms developed for the Greek population. Patients & methods: A total of 140 Greek patients participants of the EU-PACT trial for acenocoumarol, a randomized clinical trial that prospectively compared the effect of a PG dosing algorithm with a clinical dosing algorithm on the percentage of time within INR therapeutic range, who reached acenocoumarol stable dose were included in the study. Results: CYP2C9 and VKORC1 genotypes, age and weight affected acenocoumarol dose and predicted 53.9% of its variability. EU-PACT PG algorithm overestimated acenocoumarol dose across all different CYP2C9/VKORC1 functional phenotype bins (predicted dose vs stable dose in normal responders 2.31 vs 2.00 mg/day, p = 0.028, in sensitive responders 1.72 vs 1.50 mg/day, p = 0.003, in highly sensitive responders 1.39 vs 1.00 mg/day, p = 0.029). The PG algorithm previously developed for the Greek population overestimated the dose in normal responders (2.51 vs 2.00 mg/day, p < 0.001). Conclusion: Ethnic-specific dosing algorithm is suggested for better prediction of acenocoumarol dosage requirements in patients of Greek origin.
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Affiliation(s)
| | - Vana Kolovou
- Cardiology Department, Onassis Cardiac Surgery Center, Athens, Greece
| | - Genovefa Kolovou
- Cardiology Department, Onassis Cardiac Surgery Center, Athens, Greece
| | - Stavros Konstantinides
- University Cardiology Department, Medical School, Democritus University of Thrace, Alexandroupolis, Greece
| | - Efstratios Maltezos
- Second Department of Internal Medicine, Democritus University of Thrace, Alexandroupolis, Greece
| | - Anna Tavridou
- Laboratory of Pharmacology, Medical School, Democritus University of Thrace, Alexandroupolis, Greece
- Clinical Pharmacology Unit, Academic General Hospital of Evros, Alexandroupolis, Greece
| | - Dimitrios Tziakas
- University Cardiology Department, Medical School, Democritus University of Thrace, Alexandroupolis, Greece
| | - Anke H Maitland-van der Zee
- Division of Pharmacoepidemiology & Clinical Pharmacology, Department of Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands
| | - Vangelis G Manolopoulos
- Laboratory of Pharmacology, Medical School, Democritus University of Thrace, Alexandroupolis, Greece
- Clinical Pharmacology Unit, Academic General Hospital of Evros, Alexandroupolis, Greece
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Cost-effectiveness of pharmacogenetic-guided dosing of warfarin in the United Kingdom and Sweden. THE PHARMACOGENOMICS JOURNAL 2016; 16:478-84. [DOI: 10.1038/tpj.2016.41] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 04/19/2016] [Accepted: 05/02/2016] [Indexed: 01/20/2023]
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8
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Verhoef TI, Redekop WK, de Boer A, Maitland-van der Zee AH. Economic evaluation of a pharmacogenetic dosing algorithm for coumarin anticoagulants in The Netherlands. Pharmacogenomics 2016; 16:101-14. [PMID: 25616097 DOI: 10.2217/pgs.14.149] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AIM To investigate the cost-effectiveness of a pharmacogenetic dosing algorithm versus a clinical dosing algorithm for coumarin anticoagulants in The Netherlands. MATERIALS & METHODS A decision-analytic Markov model was used to analyze the cost-effectiveness of pharmacogenetic dosing of phenprocoumon and acenocoumarol versus clinical dosing. RESULTS Pharmacogenetic dosing increased costs by €33 and quality-adjusted life-years (QALYs) by 0.001. The incremental cost-effectiveness ratios were €28,349 and €24,427 per QALY gained for phenprocoumon and acenocoumarol, respectively. At a willingness-to-pay threshold of €20,000 per QALY, the pharmacogenetic dosing algorithm was not likely to be cost effective compared with the clinical dosing algorithm. CONCLUSION Pharmacogenetic dosing improves health only slightly when compared with clinical dosing. However, availability of low-cost genotyping would make it a cost-effective option.
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Affiliation(s)
- Talitha I Verhoef
- Utrecht Institute of Pharmaceutical Sciences, Division of Pharmacoepidemiology & Clinical Pharmacology, Utrecht University, Utrecht, The Netherlands
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Shahabi P, Dubé MP. Cardiovascular pharmacogenomics; state of current knowledge and implementation in practice. Int J Cardiol 2015; 184:772-795. [DOI: 10.1016/j.ijcard.2015.02.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 02/17/2015] [Accepted: 02/21/2015] [Indexed: 02/07/2023]
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10
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Janzic A, Kos M. Cost effectiveness of novel oral anticoagulants for stroke prevention in atrial fibrillation depending on the quality of warfarin anticoagulation control. PHARMACOECONOMICS 2015; 33:395-408. [PMID: 25512096 DOI: 10.1007/s40273-014-0246-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
BACKGROUND Vitamin K antagonists, such as warfarin, are standard treatments for stroke prophylaxis in patients with atrial fibrillation. Patient outcomes depend on quality of warfarin management, which includes regular monitoring and dose adjustments. Recently, novel oral anticoagulants (NOACs) that do not require regular monitoring offer an alternative to warfarin. The aim of this study was to evaluate whether cost effectiveness of NOACs for stroke prevention in atrial fibrillation depends on the quality of warfarin control. METHODS We developed a Markov decision model to simulate warfarin treatment outcomes in relation to the quality of anticoagulation control, expressed as percentage of time in the therapeutic range (TTR). Standard treatment with adjusted-dose warfarin and improved anticoagulation control by genotype-guided dosing were compared with dabigatran, rivaroxaban, apixaban and edoxaban. The analysis was performed from the Slovenian healthcare payer perspective using 2014 costs. RESULTS In the base case, the incremental cost-effectiveness ratio for apixaban, dabigatran and edoxaban was below the threshold of €25,000 per quality-adjusted life-years compared with adjusted-dose warfarin with a TTR of 60%. The probability that warfarin was a cost-effective option was around 1%. This percentage rises as the quality of anticoagulation control improves. At a TTR of 70%, warfarin was the preferred treatment in half the iterations. CONCLUSION The cost effectiveness of NOACs for stroke prevention in patients with nonvalvular atrial fibrillation who are at increased risk for stroke is highly sensitive to warfarin anticoagulation control. NOACs are more likely to be cost-effective options in settings with poor warfarin management than in settings with better anticoagulation control, where they may not represent good value for money.
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Affiliation(s)
- Andrej Janzic
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva cesta 7, 1000, Ljubljana, Slovenia
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11
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Baranova EV, Verhoef TI, Asselbergs FW, de Boer A, Maitland-van der Zee AH. Genotype-guided coumarin dosing: where are we now and where do we need to go next? Expert Opin Drug Metab Toxicol 2015; 11:509-22. [DOI: 10.1517/17425255.2015.1004053] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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12
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Pharmacogenetics of Coumarin Anticoagulant Therapy. ADVANCES IN PREDICTIVE, PREVENTIVE AND PERSONALISED MEDICINE 2015. [DOI: 10.1007/978-3-319-15344-5_11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Howard RL, French DJ, Richardson JA, O'Neill CE, Andreou MP, Brown T, Clark D, Clarke IN, Holloway JW, Marsh P, Debenham PG. Rapid detection of diagnostic targets using isothermal amplification and HyBeacon probes--a homogenous system for sequence-specific detection. Mol Cell Probes 2014; 29:92-8. [PMID: 25542839 DOI: 10.1016/j.mcp.2014.12.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 12/16/2014] [Accepted: 12/17/2014] [Indexed: 01/17/2023]
Abstract
Isothermal amplification is a rapid, simple alternative to PCR, with amplification commonly detected using fluorescently labelled oligonucleotide probes, intercalating dyes or increased turbidity as a result of magnesium pyrophosphate generation. SNP identification is possible but requires either allele-specific primers or multiple dye-labelled probes, but further downstream processing is often required for allelic identification. Here we demonstrate that modification of common isothermal amplification methods by the addition of HyBeacon probes permits homogeneous sequence detection and discrimination by melting or annealing curve analysis. Furthermore, we demonstrate that isothermal amplification and sequence discrimination is possible directly from a crude sample such as an expressed buccal swab.
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Affiliation(s)
| | | | - James A Richardson
- University of Southampton School of Chemistry, Highfield, Southampton SO17 1BJ, UK
| | - Colette E O'Neill
- University of Southampton Faculty of Medicine, Clinical and Experimental Sciences, Southampton General Hospital, Southampton SO16 6YD, UK
| | | | - Tom Brown
- University of Southampton School of Chemistry, Highfield, Southampton SO17 1BJ, UK
| | - Duncan Clark
- OptiGene Ltd., Unit 5, Blatchford Road, Horsham, RH13 5QR, UK
| | - Ian N Clarke
- University of Southampton Faculty of Medicine, Clinical and Experimental Sciences, Southampton General Hospital, Southampton SO16 6YD, UK
| | - John W Holloway
- University of Southampton Faculty of Medicine, Clinical and Experimental Sciences, Southampton General Hospital, Southampton SO16 6YD, UK
| | - Peter Marsh
- Health Protection Agency, Southampton General Hospital, Southampton SO16 6YD, UK
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14
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Verhoef TI, Redekop WK, Daly AK, van Schie RMF, de Boer A, Maitland-van der Zee AH. Pharmacogenetic-guided dosing of coumarin anticoagulants: algorithms for warfarin, acenocoumarol and phenprocoumon. Br J Clin Pharmacol 2014; 77:626-41. [PMID: 23919835 DOI: 10.1111/bcp.12220] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 07/17/2013] [Indexed: 12/13/2022] Open
Abstract
Coumarin derivatives, such as warfarin, acenocoumarol and phenprocoumon are frequently prescribed oral anticoagulants to treat and prevent thromboembolism. Because there is a large inter-individual and intra-individual variability in dose-response and a small therapeutic window, treatment with coumarin derivatives is challenging. Certain polymorphisms in CYP2C9 and VKORC1 are associated with lower dose requirements and a higher risk of bleeding. In this review we describe the use of different coumarin derivatives, pharmacokinetic characteristics of these drugs and differences amongst the coumarins. We also describe the current clinical challenges and the role of pharmacogenetic factors. These genetic factors are used to develop dosing algorithms and can be used to predict the right coumarin dose. The effectiveness of this new dosing strategy is currently being investigated in clinical trials.
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Affiliation(s)
- Talitha I Verhoef
- Department of Pharmaceutical Sciences, Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht University, Utrecht
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15
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Navarro E, Serrano-Heras G, Castaño MJ, Solera J. Real-time PCR detection chemistry. Clin Chim Acta 2014; 439:231-50. [PMID: 25451956 DOI: 10.1016/j.cca.2014.10.017] [Citation(s) in RCA: 231] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 10/09/2014] [Accepted: 10/11/2014] [Indexed: 12/28/2022]
Abstract
Real-time PCR is the method of choice in many laboratories for diagnostic and food applications. This technology merges the polymerase chain reaction chemistry with the use of fluorescent reporter molecules in order to monitor the production of amplification products during each cycle of the PCR reaction. Thus, the combination of excellent sensitivity and specificity, reproducible data, low contamination risk and reduced hand-on time, which make it a post-PCR analysis unnecessary, has made real-time PCR technology an appealing alternative to conventional PCR. The present paper attempts to provide a rigorous overview of fluorescent-based methods for nucleic acid analysis in real-time PCR described in the literature so far. Herein, different real-time PCR chemistries have been classified into two main groups; the first group comprises double-stranded DNA intercalating molecules, such as SYBR Green I and EvaGreen, whereas the second includes fluorophore-labeled oligonucleotides. The latter, in turn, has been divided into three subgroups according to the type of fluorescent molecules used in the PCR reaction: (i) primer-probes (Scorpions, Amplifluor, LUX, Cyclicons, Angler); (ii) probes; hydrolysis (TaqMan, MGB-TaqMan, Snake assay) and hybridization (Hybprobe or FRET, Molecular Beacons, HyBeacon, MGB-Pleiades, MGB-Eclipse, ResonSense, Yin-Yang or displacing); and (iii) analogues of nucleic acids (PNA, LNA, ZNA, non-natural bases: Plexor primer, Tiny-Molecular Beacon). In addition, structures, mechanisms of action, advantages and applications of such real-time PCR probes and analogues are depicted in this review.
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Affiliation(s)
- E Navarro
- Research Unit, General University Hospital, Laurel s/n, 02006 Albacete, Spain.
| | - G Serrano-Heras
- Research Unit, General University Hospital, Laurel s/n, 02006 Albacete, Spain.
| | - M J Castaño
- Research Unit, General University Hospital, Laurel s/n, 02006 Albacete, Spain.
| | - J Solera
- Internal Medicine Department, General University Hospital, Hermanos Falcó 37, 02006 Albacete, Spain.
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Maitland-van der Zee AH, Daly AK, Kamali F, Manolopoulous VG, Manolopoulos VG, Verhoef TI, Wadelius M, de Boer A, Pirmohamed M. Patients benefit from genetics-guided coumarin anticoagulant therapy. Clin Pharmacol Ther 2014; 96:15-7. [PMID: 24942396 DOI: 10.1038/clpt.2014.44] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Observational studies have overwhelmingly shown that variants in the genes CYP2C9 and VKORC1 are significant determinants of individual dose of coumarin anticoagulants needed to maintain a therapeutic international normalized ratio (INR).(1) Until recently, however, few randomized clinical trials had been performed relating to the use of genetic data to predict dosing. Three sucsh clinical trials have now reported their findings.
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Affiliation(s)
- A H Maitland-van der Zee
- Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, the Netherlands
| | - A K Daly
- Institute of Cellular Medicine, Newcastle University Medical School, Newcastle upon Tyne, UK
| | - F Kamali
- Institute of Cellular Medicine, Newcastle University Medical School, Newcastle upon Tyne, UK
| | | | - V G Manolopoulos
- Laboratory of Pharmacology, Medical School, Democritus University of Thrace, Alexandroupolis, Greece
| | - T I Verhoef
- Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, the Netherlands
| | - M Wadelius
- Department of Medical Sciences, Clinical Pharmacology, Uppsala University, Uppsala, Sweden
| | - A de Boer
- Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, the Netherlands
| | - M Pirmohamed
- The Wolfson Centre for Personalised Medicine, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
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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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Abstract
The number and use of pharmacogenetic tests to assess a patient's likelihood of response or risk of an adverse event is expanding across medical specialties and becoming more prevalent. During this period of development and translation, different approaches are being investigated to optimize delivery of pharmacogenetic services. In this paper, we review pre-emptive and point-of-care delivery approaches currently implemented or being investigated and discuss the advantages and disadvantages of each approach. The continued growth in knowledge about the genetic basis of drug response combined with development of new and less expensive testing technologies and electronic medical records will impact future delivery systems. Regardless of delivery approach, the currently limited knowledge of health professionals about genetics generally or PGx specifically will remain a major obstacle to utilization.
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Affiliation(s)
- Susanne B. Haga
- Institute for Genome Sciences & Policy, Duke University, 304 Research Drive, Box 90141, Durham, NC 27708, Tel: 919.684.0325, Fax: 919.613.6448
| | - Jivan Moaddeb
- Institute for Genome Sciences & Policy, Duke University, 304 Research Drive, Box 90141, Durham, NC 27708, Tel: 919.684.0325, Fax: 919.613.6448
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Polymorphism Detection of VKORC1 and CYP2C9 Genes for Warfarin Dose Adjustment by Real-Time PCR. ACTA ACUST UNITED AC 2014. [DOI: 10.5812/thrita.14033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Pirmohamed M, Burnside G, Eriksson N, Jorgensen AL, Toh CH, Nicholson T, Kesteven P, Christersson C, Wahlström B, Stafberg C, Zhang JE, Leathart JB, Kohnke H, Maitland-van der Zee AH, Williamson PR, Daly AK, Avery P, Kamali F, Wadelius M. A randomized trial of genotype-guided dosing of warfarin. N Engl J Med 2013; 369:2294-303. [PMID: 24251363 DOI: 10.1056/nejmoa1311386] [Citation(s) in RCA: 592] [Impact Index Per Article: 53.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND The level of anticoagulation in response to a fixed-dose regimen of warfarin is difficult to predict during the initiation of therapy. We prospectively compared the effect of genotype-guided dosing with that of standard dosing on anticoagulation control in patients starting warfarin therapy. METHODS We conducted a multicenter, randomized, controlled trial involving patients with atrial fibrillation or venous thromboembolism. Genotyping for CYP2C9*2, CYP2C9*3, and VKORC1 (-1639G→A) was performed with the use of a point-of-care test. For patients assigned to the genotype-guided group, warfarin doses were prescribed according to pharmacogenetic-based algorithms for the first 5 days. Patients in the control (standard dosing) group received a 3-day loading-dose regimen. After the initiation period, the treatment of all patients was managed according to routine clinical practice. The primary outcome measure was the percentage of time in the therapeutic range of 2.0 to 3.0 for the international normalized ratio (INR) during the first 12 weeks after warfarin initiation. RESULTS A total of 455 patients were recruited, with 227 randomly assigned to the genotype-guided group and 228 assigned to the control group. The mean percentage of time in the therapeutic range was 67.4% in the genotype-guided group as compared with 60.3% in the control group (adjusted difference, 7.0 percentage points; 95% confidence interval, 3.3 to 10.6; P<0.001). There were significantly fewer incidences of excessive anticoagulation (INR ≥4.0) in the genotype-guided group. The median time to reach a therapeutic INR was 21 days in the genotype-guided group as compared with 29 days in the control group (P<0.001). CONCLUSIONS Pharmacogenetic-based dosing was associated with a higher percentage of time in the therapeutic INR range than was standard dosing during the initiation of warfarin therapy. (Funded by the European Commission Seventh Framework Programme and others; ClinicalTrials.gov number, NCT01119300.).
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Affiliation(s)
- Munir Pirmohamed
- From the University of Liverpool (M.P., G.B., A.L.J., C.H.T., J.E.Z., P.R.W.) and Royal Liverpool and Broadgreen University Hospital National Health Service (NHS) Trust (M.P., C.H.T.), Liverpool, Whiston Hospital, Prescot (T.N.), and Newcastle upon Tyne NHS Trust (P.K.) and Newcastle University (J.B.L., A.K.D., P.A., F.K.), Newcastle upon Tyne - all in the United Kingdom; Uppsala University, Department of Medical Sciences (N.E., C.C., H.K., M.W.), Uppsala Clinical Research Center (N.E.) and Uppsala University Hospital (C.C., B.W., M.W.), Uppsala, and Enköping Hospital, Enköping (C.S.) - all in Sweden; and Utrecht University, Utrecht, the Netherlands (A.H.M.Z.)
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Abstract
PURPOSE OF REVIEW To review the most promising genetic markers associated with the variability in the safety or efficacy of warfarin and clopidogrel and highlight the verification and validation initiatives for translating clopidogrel and warfarin pharmacogenetic tests to clinical practice. RECENT FINDINGS Rapid advances in pharmacogenetics, continuous decrease in genotyping cost, development of point-of-care devices and the newly established clinical genotyping programs at several institutions hold the promise of individualizing clopidogrel and warfarin based on genotype. Guidelines have been established to assist clinicians in prescribing clopidogrel or warfarin dose based on genotype. However, the clinical utility of clopidogrel and warfarin is still limited. Accordingly, large randomized clinical trials are underway to define the role of clopidogrel and warfarin pharmacogenetics in clinical practice. SUMMARY Pharmacogenetics has offered compelling evidence toward the individualization of clopidogrel and warfarin therapies. The rapid advances in technology make the clinical implementation of clopidogrel and warfarin pharmacogenetics possible. The clinical genotyping programs and the ongoing clinical trials will help in overcoming some of the barriers facing the clinical implementation of clopidogrel and warfarin pharmacogenetics.
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Rakicevic LB, Kusic-Tisma JS, Kovac MK, Backovic DT, Radojkovic DP. Rationalized DNA sequencing-based protocol for genotyping patients receiving coumarin therapy. Scandinavian Journal of Clinical and Laboratory Investigation 2013; 73:523-7. [PMID: 23806093 DOI: 10.3109/00365513.2013.809142] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
During the last decade genetic factors affecting coumarin therapy have been extensively investigated. The most important genes appear to be CYP2C9 and VKORC1, and different studies have shown that DNA testing can dramatically improve the safety and effectiveness of the therapy. However, the implementation of pharmacogenetic testing in everyday practice is still not a reality. Facilities and ability to get results before the start of therapy are very important. The implementation of specific methodology and equipment for particular type of diagnostics can represent a serious, even impossible, financial hurdle to overcome (especially in developing countries). For this reason, the use of every tool that contributes to rationalization of the existing methods can be a considerable asset. Therefore, we set the goal to rationalize our current DNA sequencing based protocol for analysis of the VKORC1 c.-1639G> A, CYP2C9*2 and CYP2C9*3 variant alleles, in order to obtain shorter and easier procedure. Simplification of the protocol was achieved by setting up multiplex PCR and omitting DNA extraction. This rationalization of the existing DNA sequencing based procedure allows getting results in 12 hours. The new protocol was tested on 118 samples. Obtained results have shown full accordance to those obtained with previous, non-modified protocol. Therefore, given the circumstances, we consider that protocol for pharmocogenetic testing should be made more accessible - both to doctors and patients. It is one of the prerequisites in order to make genotyping prior to the therapy common practice.
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Affiliation(s)
- Ljiljana B Rakicevic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade , Serbia
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Verhoef TI, Redekop WK, Veenstra DL, Thariani R, Beltman PA, van Schie RMF, de Boer A, Maitland-van der Zee AH. Cost–effectiveness of pharmacogenetic-guided dosing of phenprocoumon in atrial fibrillation. Pharmacogenomics 2013; 14:869-83. [DOI: 10.2217/pgs.13.74] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Aim: To investigate the cost–effectiveness of pharmacogenetic-guided phenprocoumon dosing versus standard anticoagulation care in Dutch patients with atrial fibrillation. Materials & methods: Using a decision-analytic Markov model, cost–effectiveness of pharmacogenetic-guided therapy versus standard care was estimated. Results: Compared with standard care, the pharmacogenetic-guided dosing strategy increased quality-adjusted life-years (QALYs) only very slightly and increased costs by €15. The incremental cost–effectiveness ratio was €2658 per QALY gained. In sensitivity analyses, the cost of genotyping had the largest influence on the cost–effectiveness ratio. In a probabilistic sensitivity analysis, the incremental costs of genotype-guided dosing were less than €20,000 per QALY gained in 75.6% of the simulations. Conclusion: Pharmacogenetic-guided dosing of phenprocoumon has the potential to increase health slightly and may be able to achieve this in a cost-effective way. Owing to the many uncertainties it is too early to conclude whether or not patients starting phenprocoumon should be genotyped. Original submitted 20 December 2012; Revision submitted 8 April 2013
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Affiliation(s)
- Talitha I Verhoef
- Utrecht Institute of Pharmaceutical Sciences, Division of Pharmacoepidemiology & Clinical Pharmacology, Utrecht University, PO Box 80 082, 3508 TB Utrecht, The Netherlands.
| | - William K Redekop
- Institute for Medical Technology Assessment, Erasmus University, Rotterdam, The Netherlands
| | - David L Veenstra
- Department of Pharmacy, University of Washington, Seattle, Washington, USA
| | - Rahber Thariani
- Department of Pharmacy, University of Washington, Seattle, Washington, USA
| | - Peter A Beltman
- Utrecht Institute of Pharmaceutical Sciences, Division of Pharmacoepidemiology & Clinical Pharmacology, Utrecht University, PO Box 80 082, 3508 TB Utrecht, The Netherlands
| | - Rianne MF van Schie
- Utrecht Institute of Pharmaceutical Sciences, Division of Pharmacoepidemiology & Clinical Pharmacology, Utrecht University, PO Box 80 082, 3508 TB Utrecht, The Netherlands
| | - Anthonius de Boer
- Utrecht Institute of Pharmaceutical Sciences, Division of Pharmacoepidemiology & Clinical Pharmacology, Utrecht University, PO Box 80 082, 3508 TB Utrecht, The Netherlands
| | - Anke-Hilse Maitland-van der Zee
- Utrecht Institute of Pharmaceutical Sciences, Division of Pharmacoepidemiology & Clinical Pharmacology, Utrecht University, PO Box 80 082, 3508 TB Utrecht, The Netherlands
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Shahabi P, Siest G, Visvikis-Siest S. Clinical interest of point-of-care pharmacogenomic testing: clopidogrel behind warfarin. Pharmacogenomics 2013; 13:1215-8. [PMID: 22920390 DOI: 10.2217/pgs.12.85] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Daly AK. Optimal dosing of warfarin and other coumarin anticoagulants: the role of genetic polymorphisms. Arch Toxicol 2013; 87:407-20. [PMID: 23376975 DOI: 10.1007/s00204-013-1013-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2012] [Accepted: 01/17/2013] [Indexed: 12/14/2022]
Abstract
Coumarin anticoagulants, which include warfarin, acenocoumarol and phenprocoumon, are among the most widely prescribed drugs worldwide. There is now a large body of published data showing that genotype for certain common polymorphisms in the genes encoding the target vitamin K epoxide reductase (G-1639A/C1173T) and the main metabolizing enzyme CYP2C9 (CYP2C9*2 and *3 alleles) are important determinants of the individual coumarin anticoagulant dose requirement. Additional less common polymorphisms in these genes together with polymorphisms in other genes relevant to blood coagulation such as the cytochrome P450 CYP4F2, gamma-glutamyl carboxylase, calumenin and cytochrome P450 oxidoreductase may also be significant predictors of dose, especially in ethnic groups such as Africans where there have been fewer genetic studies compared with European populations. Using relevant genotypes to calculate starting dose may improve safety during the initiation period. Various algorithms for dose calculation, which also take patient age and other characteristics into consideration, have been developed for all three widely used coumarin anticoagulants and are now being tested in ongoing large randomised clinical trials. One recently completed study has provided encouraging results suggesting that calculation of warfarin dose on the basis of individual patient genotype leads to few adverse events and a higher proportion of time within the therapeutic coagulation rate window, but these findings still need confirmation.
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Affiliation(s)
- Ann K Daly
- Institute of Cellular Medicine, Newcastle University Medical School, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK.
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Daly AK, Veal GJ, Jamieson D, Coulthard S. Institutional Profile: Pharmacogenomics research at Newcastle University. Pharmacogenomics 2012; 13:1333-8. [DOI: 10.2217/pgs.12.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Newcastle University has been active in the field of pharmacogenomics/pharmacogenetics research since 1988. Research activity is based at the Faculty of Medical Sciences and is led by four professors within two separate research institutes. This article describes the various ongoing research projects and the teams involved together with our teaching activities in the subject.
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Affiliation(s)
- Ann K Daly
- Institute of Cellular Medicine, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Gareth J Veal
- Northern Institute for Cancer Research, Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - David Jamieson
- Northern Institute for Cancer Research, Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Sally Coulthard
- Northern Institute for Cancer Research, Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
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Eriksson N, Wadelius M. Prediction of warfarin dose: why, when and how? Pharmacogenomics 2012; 13:429-40. [DOI: 10.2217/pgs.11.184] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Prediction models are the key to individualized drug therapy. Warfarin is a typical example of where pharmacogenetics could help the individual patient by modeling the dose, based on clinical factors and genetic variation in CYP2C9 and VKORC1. Clinical studies aiming to show whether pharmacogenetic warfarin dose predictions are superior to conventional initiation of warfarin are now underway. This review provides a broad view over the field of warfarin pharmacogenetics from basic knowledge about the drug, how it is monitored, factors affecting dose requirement, prediction models in general and different types of prediction models for warfarin dosing.
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Affiliation(s)
- Niclas Eriksson
- Department of Medical Sciences, Clinical Pharmacology, Uppsala University, Uppsala University Hospital, entrance 61, SE-751 85 Uppsala, Sweden
| | - Mia Wadelius
- Department of Medical Sciences, Clinical Pharmacology, Uppsala University, Uppsala University Hospital, entrance 61, SE-751 85 Uppsala, Sweden
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Genetic polymorphisms affecting drug metabolism: recent advances and clinical aspects. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2012; 63:137-67. [PMID: 22776641 DOI: 10.1016/b978-0-12-398339-8.00004-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Though current knowledge of pharmacogenetic factors relevant to drug metabolism is fairly comprehensive and this should facilitate translation to the clinic, there are a number of gaps in knowledge. Recent studies using both conventional and novel approaches have added to our knowledge of pharmacogenetics of drug metabolism. Genome-wide association studies have provided new insights into the major contribution of cytochromes P450 to response to therapeutic agents such as coumarin anticoagulants and clopidogrel as well as to caffeine and nicotine. Recent advances in understanding of factors affecting gene expression, both regulation by transcription factors and by microRNA and epigenetic factors, have added to understanding of variation in expression of genes such as CYP3A4 and CYP2E1. The implementation of testing for pharmacogenetic polymorphisms in prescription of selected anticancer drugs and cardiovascular agents is considered in detail, with current controversies and barriers to implementation of pharmacogenetic testing assessed. Though genotyping for thiopurine methyltransferase is now common prior to prescription of thiopurines, genotyping for other pharmacogenetic polymorphisms prior to drug prescription remains uncommon. However, it seems likely that it will become more widespread as both increased evidence that certain pharmacogenetic tests are valuable and cost-effective and more accessible genotyping methods become available.
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