Daily Vitamin K in Patients on Warfarin With Unstable INRs

Anticoagulants Clinical Trial

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00287313
• Other study ID #: 05-MED-491
• Status: Completed
• Phase: N/A
• First received: February 3, 2006
• Last updated: January 11, 2010
• Start date: October 2005
• Est. completion date: May 2006

Study information

• Verified date: January 2010
• Source: University of North Carolina, Chapel Hill
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Food and Drug Administration
• Study type: Interventional

Clinical Trial Summary

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.

Description:

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 15
• Est. completion date: May 2006
• Est. primary completion date: May 2006
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years and older

Eligibility

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

Study Design

Allocation: Non-Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment

Related Conditions & MeSH terms

• Anticoagulants
• Warfarin

Intervention

Drug:
• Vitamin K

Locations

Country	Name	City	State
United States	University of North Carolina at Chapel Hill	Chapel Hill	North Carolina

Sponsors (1)

Lead Sponsor	Collaborator
University of North Carolina, Chapel Hill

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Number of warfarin adjustments required in each phase
Primary	Time in therapeutic, sub-, and supra-therapeutic range
Primary	Variance/SD of INRs for each patient
Primary	Adherence assessed by pill counts and pharmacy record review
Primary	Thrombotic/bleeding episodes