Prospective Genotyping For Total Hip or Knee Replacement Patients Receiving Warfarin (Coumadin)

NCT ID: NCT00634907

Last Updated: 2017-06-08

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 263 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2006-09-30
• Study Completion Date: 2008-10-31

Brief Summary

Several human genes affect how medications are metabolized by the body. It is believed that knowledge of variations of these genes can help health care providers better manage an anticoagulation medicine called warfarin (Coumadin®)and as a result decrease patient problems with bleeding or the development of blood clots. This study was designed to evaluate if genetic testing can improve warfarin initiation better than usual care.

Detailed Description

This study was completed in 2008 and was published. Consult the citation link for more details.

Conditions

Venous Thromboembolism; Bleeding

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

Pharmacogenetic-based warfarin dosing

Pharmacogenetic-based warfarin dosing: Warfarin dosing based on formula that incorporates genetic testing results.

NOTE: Standard of care for elective knee and hip replacement at our institution is to receive post-operative warfarin thromboprophylaxis. Administration of warfarin was not specific to this study, nor was the duration of prophylaxis, however, warfarin dosing was influenced by the study arm, as noted above.

Group Type: EXPERIMENTAL

Pharmacogenetic-based warfarin dosing

Intervention Type: GENETIC

Prior to elective joint replacement surgery a blood sample is collected for genetic information(genotyping)which was used for calculating warfarin doses for patients randomized to the cytochrome arm. Outcomes in terms of efficacy, safety, and management of warfarin were compared between this group and the group in which warfarin doses are determined per usual care.

NOTE: Standard of care for elective knee and hip replacement at our institution is to receive post-operative warfarin thromboprophylaxis. Administration of warfarin was not specific to this study, nor was the duration of prophylaxis, however, warfarin dosing was influenced by the study arm as noted above.

Standard of care (control)

Control or "usual care" warfarin dosing

NOTE: Standard of care ("usual care") for elective knee and hip replacement at our institution is to receive post-operative warfarin thromboprophylaxis. Administration of warfarin was not specific to this study, nor was the duration of prophylaxis, however, warfarin dosing was influenced by the study arm, as noted above.

Group Type: ACTIVE_COMPARATOR

Usual care warfarin dosing

Intervention Type: OTHER

For patients in arm 2, the control group, warfarin dosing is per usual care. Outcomes in terms of safety, efficacy, and warfarin management was compared to that of patients in the other arm, who receive warfarin dosing based on genotyping.

NOTE: Standard of care for elective knee and hip replacement at our institution is to receive post-operative warfarin thromboprophylaxis. Administration of warfarin was not specific to this study, nor was the duration of prophylaxis, however, warfarin dosing was influenced by the study arm as noted above.

Interventions

Pharmacogenetic-based warfarin dosing

Prior to elective joint replacement surgery a blood sample is collected for genetic information(genotyping)which was used for calculating warfarin doses for patients randomized to the cytochrome arm. Outcomes in terms of efficacy, safety, and management of warfarin were compared between this group and the group in which warfarin doses are determined per usual care.

NOTE: Standard of care for elective knee and hip replacement at our institution is to receive post-operative warfarin thromboprophylaxis. Administration of warfarin was not specific to this study, nor was the duration of prophylaxis, however, warfarin dosing was influenced by the study arm as noted above.

Intervention Type: GENETIC

Usual care warfarin dosing

For patients in arm 2, the control group, warfarin dosing is per usual care. Outcomes in terms of safety, efficacy, and warfarin management was compared to that of patients in the other arm, who receive warfarin dosing based on genotyping.

NOTE: Standard of care for elective knee and hip replacement at our institution is to receive post-operative warfarin thromboprophylaxis. Administration of warfarin was not specific to this study, nor was the duration of prophylaxis, however, warfarin dosing was influenced by the study arm as noted above.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• Participants were otherwise healthy adults (≥ 18 years of age) who were planning total hip or knee replacement or revision surgery at the University of Utah Hospital, and scheduled a pre-operative office visit at the University of Utah Orthopaedic Center.

Exclusion Criteria

• Blood transfusion in previous two weeks
• Participant is already taking warfarin
• Pre-operative INR > 4.0
• Pre-operative bilirubin > 2.4 mg/dL
• Current active cancer diagnosis with ongoing treatment
• Concomitant medications known to exert a major interaction with warfarin such as septra, metronidazole, tramadol, amiodarone, ciprofloxacin, or cimetidine.

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Gwen McMillin

OTHER

Sponsor Role: lead

Responsible Party

Gwen McMillin

Medical Director Toxicology and Trace Minterals, Department of Pathology, ARUP Laboratories

Responsibility Role: SPONSOR_INVESTIGATOR

Principal Investigators

Gwen McMillin, PhD

Role: PRINCIPAL_INVESTIGATOR

ARUP Laboratories

Locations

University of Utah Health Care

Salt Lake City, Utah, United States

Countries

United States

References

McMillin GA, Melis R, Wilson A, Strong MB, Wanner NA, Vinik RG, Peters CL, Pendleton RC. Gene-based warfarin dosing compared with standard of care practices in an orthopedic surgery population: a prospective, parallel cohort study. Ther Drug Monit. 2010 Jun;32(3):338-45. doi: 10.1097/FTD.0b013e3181d925bb.

Reference Type: RESULT

PMID: 20386359 (View on PubMed)

Other Identifiers

00019469

Identifier Type: -

Identifier Source: org_study_id