Try our beta test site
IMPORTANT: Listing of a study on this site does not reflect endorsement by the National Institutes of Health. Talk with a trusted healthcare professional before volunteering for a study. Read more...

Genetic Determinants of Warfarin Anticoagulation Effect

This study is currently recruiting participants. (see Contacts and Locations)
Verified March 2017 by Hadassah Medical Organization
United States - Israel Binational Science Foundation
Israel Science Foundation
Ministry of Health, Israel
Information provided by (Responsible Party):
Yosef Caraco, Hadassah Medical Organization Identifier:
First received: September 11, 2005
Last updated: March 3, 2017
Last verified: March 2017

The response to warfarin varies greatly among individuals. Some of this variability can be ascribed to genetic polymorphisms in the gene encoding for CYP2C9, the enzyme mediating the metabolism of S warfarin. In addition genetic polymorphism in other genes (i.e. VKORC1, factor VII) have been shown to account for some of the variability in the response to warfarin irrespective of CYP2C9.The present study has several segments:

  1. Evaluation of the relationship between genetic polymorphisms in the genes encoding for CYP2C9, VKORC1 and factor VII and warfarin maintenance dose at steady state. This study is a confirmation of previous data in our own population.
  2. Evaluation of relationship between genetic polymorphisms in the genes encoding for CYP2C9, VKORC1 and factor VII and warfarin loading dose during the induction period.
  3. Testing the hypothesis that warfarin loading based on the individual's combined CYP2C9, VKORC1 and factor VII genotype may be more efficient and associated with reduced adverse drug effects.

Condition Intervention
Venous Thrombosis
Pulmonary Embolism
Atrial Fibrillation
Drug: Warfarin

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single Blind (masked role unspecified)
Primary Purpose: Treatment
Official Title: Warfarin Induction Regimen Based Upon CYP2C9, VKORC1 Factor VII Genotyping, PMR and INR Monitoring, as Compared to the Conventional Regimen: a Prospective Controlled Study

Resource links provided by NLM:

Further study details as provided by Hadassah Medical Organization:

Primary Outcome Measures:
  • Pharmacokinetic end points: [ Time Frame: 1-4 months ]
  • Warfarin clearance and formation clearance of 7-hydroxy-warfarin at steady state [ Time Frame: 1-4 months ]
  • Pharmacodynamic. [ Time Frame: 1-4 months ]
  • Maintenance dose of warfarin at steady state. [ Time Frame: 1-4 months ]
  • Time to reach INR > 2. [ Time Frame: 1-4 months ]
  • Time to reach pharmacodynamic steady state. [ Time Frame: 1-4 months ]
  • Time spent at therapeutic INR <3 and >2. [ Time Frame: 1-4 months ]
  • Time spent at INR >3. [ Time Frame: 1-4 months ]
  • Time spent at INR <2. [ Time Frame: 1-4 months ]
  • The incidence of minor and major bleeding episodes. [ Time Frame: 1-4 months ]

Estimated Enrollment: 500
Study Start Date: August 2002
Estimated Study Completion Date: December 2020
Estimated Primary Completion Date: December 2020 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Genetic Drug: Warfarin
Experimental: Control Drug: Warfarin


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Patients in whom warfarin is about to be initiated
  • Desired therapeutic range >2 and <3

Exclusion Criteria:

  • Refusal to participate in the study
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00162435

Contact: Yoseph Caraco, MD 00 972 2 6778584

Hadassah Medical Organization Recruiting
Jerusalem, Israel
Contact: Arik Tzukert, DMD    00 972 2 6776095   
Contact: Hadas Lemberg, PhD    00 972 2 6777572   
Principal Investigator: Yoseph Caraco, MD         
Sponsors and Collaborators
Hadassah Medical Organization
United States - Israel Binational Science Foundation
Israel Science Foundation
Ministry of Health, Israel
Principal Investigator: Yoseph Caraco, MD Hadassah Medical Organization
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Yosef Caraco, Head, Clinical Pharmacology Unit, Division of Medicine, Hadassah Medical Organization Identifier: NCT00162435     History of Changes
Other Study ID Numbers: yc19553-HMO-CTIL
Study First Received: September 11, 2005
Last Updated: March 3, 2017

Additional relevant MeSH terms:
Atrial Fibrillation
Pulmonary Embolism
Venous Thrombosis
Arrhythmias, Cardiac
Heart Diseases
Cardiovascular Diseases
Pathologic Processes
Embolism and Thrombosis
Vascular Diseases
Lung Diseases
Respiratory Tract Diseases
Anticoagulants processed this record on April 28, 2017