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The Effect of Medication Timing on Anticoagulation Stability in Users of Warfarin: The "INRange" RCT

NCT02376803 · Status: COMPLETED · Phase: PHASE4 · Type: INTERVENTIONAL · Enrollment: 217

Last updated 2018-05-04

No results posted yet for this study

Summary

Warfarin is an anticoagulant medication that is highly effective at preventing clotting disorders but which has a narrow therapeutic window. If warfarin is under effective patients are at risk of stroke, if it is over effective patients are at risk of bleeding complications. Physicians routinely and regularly measure a blood test (called the "INR") that determines the effectiveness of warfarin and have a range of test values (the "therapeutic range") in which they try to keep the patient. By convention warfarin is taken at dinnertime, however this is the same time of day that highly variable consumption of dietary vitamin K occurs (found largely in green leafy vegetables) and vitamin K alters the effectiveness of warfarin. Given vitamin K has a very short half-life (i.e. it is only active for a short period of time after it is ingested) it may make more sense to take warfarin in the morning (when very little vitamin K is ingested) to produce a more consistent drug effect. The purpose of this study is to determine whether switching current warfarin users from evening to morning dosing decreases time spent outside the therapeutic INR range.

Conditions

  • Atrial Fibrillation
  • Thrombus Due to Heart Valve Prosthesis
  • Deep Venous Thrombosis
  • Thromboembolism
  • DVT

Interventions

DRUG

Warfarin

Morning vs Evening administration

Sponsors & Collaborators

  • Vancouver Coastal Health Research Institute

    collaborator OTHER

  • University of Alberta

    lead OTHER

Principal Investigators

  • Scott R Garrison, MD PhD · University of Alberta

Study Design

Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Model
PARALLEL

Eligibility

Min Age
18 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2015-02-28
Primary Completion
2016-09-30
Completion
2018-04-27

Countries

  • Canada

Study Locations

More Related Trials

Entities

Diseases

Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT02376803 on ClinicalTrials.gov