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Completed

NCT Number: NCT00287313

Daily Vitamin K in Patients on Warfarin With Unstable INRs

The purpose of this study is to determine if daily Vitamin K supplementation stabilizes INRs in patients taking warfarin with a history of frequent dose changes or variable INRs.

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Key information

Conditions

Anticoagulants Warfarin

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of North Carolina at Chapel Hill

Chapel Hill, North Carolina, 27599, United States

About this study

Consistent daily Vitamin K intake may contribute to the stabilization of INR values in patients with unstable INRs on warfarin therapy. Subjects with unstable INRs will be identified from the existing patient records of the UNC Anticoagulation Clinics. Eligible subjects will sign an informed consent form and will receive a point-of-care (POC) INR monitoring device. They will undergo 9 weeks of home INR monitoring via the POC device (with monthly clinic follow-up). They will subsequently be provided with 500 mcg Vitamin K tablets to be taken once daily. Weekly POC INR monitoring with monthly clinic follow-up will continue for an additional 8 weeks.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Patient of UNC Anticoagulation Clinic with INR target of 2.0-3.0 and at least 9 months on uninterrupted warfarin
  • Unstable INRs for the past 6 months, defined as a minimum number of warfarin dose changes of 3
  • Patient demonstration of proper POC device technique on 2 measurements during one teaching session with investigator
  • Age greater than or equal to 18 years

Exclusion criteria

  • Stroke or TIA within the previous 12 months
  • VTE within the last 3 months
  • Antiphospholipid antibody syndrome
  • Pregnant patients, since warfarin is contraindicated during pregnancy

Treatment and study plan

Vitamin K

Drug

Primary outcomes

  1. Number of warfarin adjustments required in each phase

  2. Time in therapeutic, sub-, and supra-therapeutic range

  3. Variance/SD of INRs for each patient

  4. Adherence assessed by pill counts and pharmacy record review

  5. Thrombotic/bleeding episodes

Sponsors and collaborators

Lead sponsor

University of North Carolina, Chapel Hill

Other

Registry information

Official study title

Use of Daily Vitamin K Supplementation in Patients on Warfarin With a History of Frequent Dose Changes or Variable INRs

Important dates

Study start
2005
Primary completion
2006
Study completion
2006
First posted
Feb 6, 2006
Registry last updated
Jan 12, 2010

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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