A Multicentre Study of Low Dose Oral Vitamin K for INR Control in Patients Receiving Warfarin
试验速览
- 阶段
- 3 期
- 状态
- 已完成
- 入组人数
- 235
- 试验地点
- 4
- 主要终点
- When compared with placebo does the addition of 150 micrograms of daily vitamin K to "usual warfarin therapy" improve anticoagulant control as measured by "time in the therapeutic range"?
研究概览
简要总结
Warfarin is highly effective for the prevention of both first and recurrent thrombotic events, however even minor excursions outside the reference INR range of 2.0 to 3.0 are associated with bleeding or thrombotic complications. The importance of maintaining the INR within the desired interval has led to the concept of "time in therapeutic range (TTR)" - the total proportion of time that the INR is between 2.0 and 3.0. The investigators propose a multicentre, double blind, randomized trial which will determine if 0.150 mg of oral vitamin K increases time in the therapeutic range for patients receiving warfarin.
详细描述
What is/are the principal research objective(s) and question(s) to be addressed? Research Objectives: Our broad objective is to improve the quality of anticoagulant care for patients receiving warfarin. Our specific objective is to determine if we can improve the TTR with LDVK, a non-toxic, inexpensive and easily administered medication.
Hypothesis: We hypothesize that patients receiving vitamin K will have a higher TTR than those receiving placebo. In a mechanistic study we proposed that VKORC1 and CYP2C9 genotype will modulate the impact of vitamin K on INR control.
Research questions:
Efficacy (primary): When compared with placebo does the addition of 150 micrograms of daily vitamin K to "usual warfarin therapy" improve anticoagulant control as measured by "time in the therapeutic range"? Safety (Secondary): Does LDVK increase the frequency of adverse clinical events, including thromboembolism? Does LDVK reduce the risk of major and/or all bleeding? Mechanistic (Hypothesis generating): Do VKORC1 and CYP2C9 genotypes modulate the effect vitamin K on INR stability?
Study design:
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Warfarin therapy administered to a target INR of 2.0 to 3.0
排除标准
- •Out of range INR on day of screening - enrolment will only occur if the patient's INR on the day of screening is between 1.8 and 3.4 (inclusive) - if the INR is outside this range the patient will be re-screened when the INR is within this range.
- •Recent warfarin initiation - all patients must have received warfarin for a minimum of 3 months
- •Planned termination or extended temporary interruption of warfarin within 6 months or anticipated survival of less than 6 months
- •Known severe liver disease, known excess alcohol consumption , known malabsorption syndrome or inability to take oral medications
- •Use of medications known to interfere with warfarin and whose dose is likely to change over the course of the study (e.g. barbiturates, rifampin etc.)
- •Known allergy to vitamin K
- •Inability or unwillingness to follow study procedures or provide consent
- •Prior participation in this study, or participating in a competing study which may impact INR control
研究组 & 干预措施
Low dose vitamin K + usual warfarin
Low dose oral vitamin K (0.150 mg orally once daily) + warfarin continuation with usual warfarin monitoring
干预措施: Phytonadione (Vitamin K1) (Drug)
Usual warfarin therapy + placebo
Patients continue usual warfarin and take one placebo per day
干预措施: Placebo (Drug)
结局指标
主要结局
When compared with placebo does the addition of 150 micrograms of daily vitamin K to "usual warfarin therapy" improve anticoagulant control as measured by "time in the therapeutic range"?
时间窗: 7 Months
次要结局
- Does low dose Vitamin K (LDVK) increase the frequency of adverse clinical events, including thromboembolism and major and/or all bleeding?(7 Months)
研究者
Mark Crowther
Vice President, Research
St. Joseph's Healthcare Hamilton