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The Association of Warfarin Dosage and Plasma Enantiomer Concentration With the Gene Polymorphisms of CYP and VKOR

NCT00247702 · Status: UNKNOWN · Phase: NA · Type: INTERVENTIONAL · Enrollment: 120

Last updated 2005-11-02

No results posted yet for this study

Summary

Oral warfarin anticogulation for the prevention and treatment of patients with venous thromboembolism is one of the most used therapies in clinical practice. Patients require different dosage to achieve the target therapeutic anticoagulation. Optimal dosage and bleeding complication are two most clinical concerns. Besides of multiple individual factors (e.g. age, dietary intake, vitamin supplement, drug compliance etc.), some genetic factors may determine the drug requirement and safety.

The cytochrome P450 CYP2C9 is a liver enzyme required for the oxidative metabolism of warfarin. The vitamin K epoxide redutase (VKOR) is a liver enzyme associated with the reuse of the oxidative hydroquinone form of vitamin K. The VKOR enzyme is the target of warfarin. Recent studies revealed both genes may determine the pharmacodynamic of warfarin anticogualation. To date, there are more than thirteen identified polymorphism at CYP2C9 gene. Majority of those variant polymorphisms may decrease the warfarin requirement. The VKOR complex subunit 1 (VKORC1) is a newly identified gene. Some polymorphisms also were reported.

As we know, the Chinese patients need a lower dosage of warfarin in comparison with the Caucasian patients. We are interested in finding the genetic causes of Taiwneses Chinese patients. In our study we will first identify the polymorphism patterns of these two genes in normal population. Then, we will try to find the association between these polymorphism and patient warfarin requirement. Our pharmacogenetics study will be valuable for prevention of bleeding complication of warfarin treatment in Chinese population.

Conditions

  • Deep Venous Thromboembolism

Interventions

DRUG

warfarin

Sponsors & Collaborators

  • National Taiwan University Hospital

    lead OTHER

Principal Investigators

  • Tasy Wei, Doctor · National Taiwan Univerisity Hospital

Study Design

Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Model
SINGLE_GROUP

Eligibility

Min Age
18 Years
Max Age
80 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2005-07-31
Completion
2006-06-30

Countries

  • Taiwan

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT00247702 on ClinicalTrials.gov