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

Gwen McMillin

Status: Completed

Conditions: Venous Thromboembolism; Bleeding

Treatments: Genetic: Pharmacogenetic-based warfarin dosing; Other: Usual care warfarin dosing

Study type: Interventional

Funder types: Other

Identifiers

NCT00634907

00019469

Details and patient eligibility

About

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.

Full description

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

Enrollment: 263 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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263 participants in 2 patient groups

Pharmacogenetic-based warfarin dosing

Experimental group

Description:

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.

Treatment:

Genetic: Pharmacogenetic-based warfarin dosing

Standard of care (control)

Active Comparator group

Description:

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.

Treatment:

Other: Usual care warfarin dosing