Deep Venous ThromboembolismNCT00247702
The Association of Warfarin Dosage and Plasma Enantiomer Concentration With the Gene Polymorphisms of CYP and VKOR
A study testing warfarin in people with Deep Venous Thromboembolism, run by National Taiwan University Hospital at 1 site in Taiwan.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 80 years
- Conditions the study is for
- Deep Venous Thromboembolism
- What is being tested?
- warfarin
- How many people
- 120 participants
- Where
- 1 siteTaiwan
- Study dates
- Jul 2005to Jun 2006
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 80 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Use warfarin therapy for at least two months before study
- Stable INR value during recent three months
Who cannot join
- higher age(>80 y/o)
- liver and renal dysfunction
- alcohol abuse
- BMI<18kg/m2
- coadministered medicine that can affect pharmacokinetics or pharmacodynamics of warfarin
Trial locations and contacts
1 site in 1 country.
Taiwan1 site, 1 recruiting
- Recruiting
National Taiwan University Hospital
Taipei, 100
Tsay Wei, Doctor, 886-2-23123456 ext. 5040, woei@ha.mc.ntu.edu.tw
About this study
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.
- Conditions
- Deep Venous Thromboembolism
- Being tested
- warfarin
- Keywords
- CYP2C9, VKORC1, polymorphism, warfarin
- Medical subject headings
- Vitamin K-Dependent Clotting Factors, Combined Deficiency Of, Type 2
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
warfarinDrug
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Nov 2005 (estimated)
- Study startJul 2005
- Study completionJun 2006
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Deep Venous ThromboembolismStudies of the same condition, open and under way.
- More trials run by National Taiwan University HospitalThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 120 participants
Sponsor and investigators
- Lead sponsor
- National Taiwan University Hospital
- Sponsor type
- University, hospital or other
- Investigators
- Tasy Wei, Doctor, Study chair, National Taiwan Univerisity Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00247702
- Sponsor's protocol ID
- 940609
- Status last verified
- Jul 2005
- First submitted
- 1 Nov 2005
- Last updated
- 2 Nov 2005
- Results posted
- No
Study at a glance
From the registry record, last updated by the sponsor on 2 Nov 2005. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Study of the Association of Warfarin Dosage and Plasma Enantiomer Concentration With the Gene Polymorphisms of CYP and VKOR
- ClinicalTrials.gov ID
- NCT00247702
- Acronym / sponsor ID
- 940609
- Conditions
- Deep Venous Thromboembolism
- Keywords
- CYP2C9, VKORC1, polymorphism, warfarin
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 120 participants
- Lead sponsor
- National Taiwan University HospitalUniversity, hospital or other
- Study start
- Jul 2005
- Study completion
- Jun 2006
- First posted
- 2 Nov 2005 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Single group
- Masking
- None (open label)
Who may qualify
- Ages
- 18 to 80 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Use warfarin therapy for at least two months before study
- Stable INR value during recent three months
Key exclusion criteria (5 listed)
- higher age(>80 y/o)
- liver and renal dysfunction
- alcohol abuse
- BMI<18kg/m2
- coadministered medicine that can affect pharmacokinetics or pharmacodynamics of warfarin
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| warfarin | Drug | – |
Primary outcome
Not reported in the source record.
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Nov 2005.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Tasy Wei, Doctor study chair
National Taiwan Univerisity Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing warfarin in people with Deep Venous Thromboembolism, run by National Taiwan University Hospital at 1 site in Taiwan.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: status not confirmed, as of the sponsor's last update on 2 Nov 2005. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Taiwan. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Tsay Wei, Doctor (886-2-23123456 ext. 5040, woei@ha.mc.ntu.edu.tw), or a site near the patient. AzTrials does not enrol participants or take referrals.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Nov 2005.