Recruiting

Warfarin with Vitamin K

Sponsor:

University of Michigan

Code:

NCT07515664

Conditions

Anticoagulant Therapy

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Vitamin K

Warfarin (standard without loading)

Warfarin (standard with loading)

Study Details

Brief summary:

This is a feasibility study of uninterrupted warfarin with a one time dose of Vitamin K before a surgical procedure.

Conditions

Anticoagulant Therapy

Study ID

NCT07515664

Start date

Jul 3, 2025

Status verified date

Apr, 2026

Completion date

Aug, 2026

Anticipated

Primary completion date

Aug, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Warfarin therapy for ≥3 months
  • Use of home INR testing equipment
  • Scheduled for a surgical procedure that requires INR ≤ 1.5 (typically achieved with warfarin interruption)
  • INR ≤ 4 on day 7-10 prior to procedure

Exclusion Criteria:

  • Surgical procedure does not require INR ≤1.5 (typically achieved with warfarin interruption)
  • Surgical procedure with a high risk of bleeding or complications (urologic procedures, bronchoscopy, epidural injections, nerve blocks, spinal surgery)
  • Warfarin therapy for < 3 months
  • Lack of English language proficiency
  • Use of a Heartmate II or HVAD left ventricular assist device
  • Recent thrombotic event (within 3 months)
  • CHA2DS2-VASc score >6
  • INR >4 on day 7-10 prior to procedure
  • Hypersensitivity to any component of Vitamin K or simple syrup (used in the compounding process)

Study Design

Enrollment

20 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Standard Warfarin Dosing with Vitamin K

Patients will receive their standard warfarin dosing before, during, and after their procedure. This is in addition to a one time dose of oral vitamin K pre-procedure.

experimental: Loading Warfarin Dosing with Vitamin K

Patients will receive their standard warfarin dosing before and during their procedure. On the night following the procedure, they will receive a one time loading dose of warfarin (twice their normal dose). Patients will then resume normal dosing of warfarin. This is in addition to a one time dose of oral vitamin K pre-procedure.

Interventions

Vitamin K

10 mg of oral vitamin K will be given approximately 36-48 hours before procedure.

Warfarin (standard without loading)

Patients receive their standard warfarin dosing without interruption.

Warfarin (standard with loading)

Patients receive their standard warfarin dosing without interruption; patients also receive a one time loading dose (twice normal dose) of warfarin on the evening following their procedure.

Primary outcome measure

  • Feasibility of patient recruitment [ Time Frame: Within two weeks (from outreach to five days prior to procedure) ]
  • INR reversal [ Time Frame: Within 12 hours prior to procedure ]

Central Contacts and Locations

Central contacts

Geoffrey Barnes, MD

734 936-4000gbarnes@med.umich.edu

Locations

Michigan Medicine

Recruiting

Ann Arbor, Michigan, United States, 48109

Contacts

Geoffrey Barnes, MD

734 936-4000gbarnes@med.umich.edu

More Information

Sponsor

University of Michigan

Last update posted

Apr 13, 2026

Last verified

Apr, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by University of Michigan on 2026-04-13.