Deep Venous Thromboembolism Clinical Trial
Official title:
Study of the Association of Warfarin Dosage and Plasma Enantiomer Concentration With the Gene Polymorphisms of CYP and VKOR
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.
| Status | Recruiting |
| Enrollment | 120 |
| Est. completion date | June 2006 |
| Est. primary completion date | |
| Accepts healthy volunteers | No |
| Gender | Both |
| Age group | 18 Years to 80 Years |
| Eligibility |
Inclusion Criteria: - Use warfarin therapy for at least two months before study - Stable INR value during recent three months Exclusion Criteria: - higher age(>80 y/o) - liver and renal dysfunction - alcohol abuse - BMI<18kg/m2 - coadministered medicine that can affect pharmacokinetics or pharmacodynamics of warfarin |
Allocation: Randomized, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment
| Country | Name | City | State |
|---|---|---|---|
| Taiwan | National Taiwan University Hospital | Taipei |
| Lead Sponsor | Collaborator |
|---|---|
| National Taiwan University Hospital |
Taiwan,