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The Clinical and Economic Impact of Pharmacogenomic Testing of Warfarin Therapy in Typical Community Practice Settings

Information source: Medco Health Solutions, Inc.
ClinicalTrials.gov processed this data on August 23, 2015
Link to the current ClinicalTrials.gov record.

Condition(s) targeted: Embolism and Thrombosis; Embolism; Vascular Diseases; Warfarin; Venous Thromboembolism; Thrombosis; Thromboembolism

Intervention: CYP 2C9 and VKORC1 Testing for Warfarin (Other)

Phase: N/A

Status: Completed

Sponsored by: Medco Health Solutions, Inc.

Official(s) and/or principal investigator(s):
Robert Epstein, MD, MS, Principal Investigator, Affiliation: Medco Health Solutions, Inc.


The purpose of this quasi-experiment study, which could also be classified as a prospective observational intervention study, is to assess the impact of cytochrome P450 2C9 (CYP 2C9) and vitamin K epoxide reductase complex, subunit 1 (VKORC1) testing within a primary patient care setting.

Clinical Details

Official title: in Typical Community Practice Settings

Study design: Observational Model: Cohort, Time Perspective: Prospective

Primary outcome: The primary objective of the study is to determine whether the addition of genotyping to usual care will reduce the hospitalization rates for hemorrhage or thromboembolism related to warfarin use during the first 6 months of treatment.

Secondary outcome: The secondary objective is to determine physician and patient acceptance of the technology.

Detailed description: Anticoagulation therapy with warfarin is the most common mode of treatment and prophylaxis for venous and arterial thromboembolic conditions. Warfarin is metabolized in the liver by the cytochrome P450 system, the cytochrome P450 2C9 (CYP 2C9) isoenzyme specifically, and polymorphisms in the CYP 2C9 gene have been associated with changes in metabolic function of the translated isoenzyme . These polymorphisms result in reduced metabolism of warfarin as compared to subjects having the wild type gene, consequently leading to systemic accumulation of warfarin; it is theorized that this leads to higher risk of adverse events. Other allelic variations have also been linked to changes in vitamin K conservation through their effects on vitamin K epoxide reductase complex, subunit 1 (VKORC1) . The combined impact of CYP 2C9 and VKORC1 polymorphisms on warfarin's pharmacology have recently been reported. It is hypothesized that evaluation of genomic allelic type guided warfarin dosing will reduce thromboembolic and bleeding risks associated with warfarin therapy, and that adoption of a genetic testing strategy in a primary patient care setting would improve warfarin effectiveness and patient safety, and reduce costs to health care payers.


Minimum age: 40 Years. Maximum age: 75 Years. Gender(s): Both.


Inclusion Criteria:

- Female and male age range of 40-75

- Patients who are in the induction phase of warfarin

- Patients receiving warfarin to prevent or treat thromboembolic conditions (e. g., post

orthopedic surgery prophylaxis, deep venous thrombosis, atrial fibrillation, pulmonary embolism, heart failure)

- Patient willing to provide informed consent prior to the specimen collection


- Patient whose physician is willing to order the genetic test

Exclusion Criteria:

- Age < 40 or > 75

- Previous use of warfarin within 180 days of initiating new warfarin therapy

- Hospitalized for seven or more days before first claim for warfarin

- Previous history of genetic testing for warfarin therapy

- Known hypersensitivity to warfarin

- Patient or physician refusal to participate in the study

- Patients using warfarin residing in Olmsted County, MN

Locations and Contacts

Medco Health Solutions, Inc., Franklin Lakes, New Jersey 07003, United States
Additional Information

Starting date: July 2007
Last updated: November 15, 2010

Page last updated: August 23, 2015

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