1. Long-term anticoagulant effects of the CYP2C9 and VKORC1 genotypes in acenocoumarol users.
- Author
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Verhoef TI, Redekop WK, Buikema MM, Schalekamp T, Van Der Meer FJ, Le Cessie S, Wessels JA, Van Schie RM, De Boer A, Teichert M, Visser LE, and Maitland-Van Der Zee AH
- Subjects
- Acenocoumarol administration & dosage, Acenocoumarol adverse effects, Aged, Anticoagulants administration & dosage, Anticoagulants adverse effects, Aryl Hydrocarbon Hydroxylases metabolism, Cytochrome P-450 CYP2C9, Drug Administration Schedule, Drug Dosage Calculations, Drug Monitoring methods, Female, Gene Frequency, Genotype, Humans, International Normalized Ratio, Male, Medication Errors prevention & control, Mixed Function Oxygenases metabolism, Netherlands, Pharmacogenetics, Phenotype, Polymorphism, Genetic, Predictive Value of Tests, Risk Assessment, Risk Factors, Time Factors, Vitamin K Epoxide Reductases, Acenocoumarol pharmacokinetics, Anticoagulants pharmacokinetics, Aryl Hydrocarbon Hydroxylases genetics, Blood Coagulation drug effects, Mixed Function Oxygenases genetics
- Abstract
Background: The required acenocoumarol dose and the risk of underanticoagulation and overanticoagulation are associated with the CYP2C9 and VKORC1 genotypes. However, the duration of the effects of these genes on anticoagulation is not yet known., Objectives: In the present study, the effects of these polymorphisms on the risk of underanticoagulation and overanticoagulation over time after the start of acenocoumarol were investigated., Patients/methods: In three cohorts, we analyzed the relationship between the CYP2C9 and VKORC1 genotypes and the incidence of subtherapeutic or supratherapeutic International Normalized Ratio (INR) values (< 2 and > 3.5) or severe overanticoagulation (INR > 6) for different time periods after treatment initiation., Results: Patients with polymorphisms in CYP2C9 and VKORC1 had a higher risk of overanticoagulation (up to 74%) and a lower risk of underanticoagulation (down to 45%) in the first month of treatment with acenocoumarol, but this effect diminished after 1-6 months., Conclusions: Knowledge of the patient's genotype therefore might assist physicians to adjust doses in the first month(s) of therapy., (© 2012 International Society on Thrombosis and Haemostasis.)
- Published
- 2012
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