Pharmacogenetic Dosing of Warfarin

Completed

Phase 3 Results N/A

Trial Description

Purpose:
Warfarin is now the most commonly used oral anticoagulant. This drug has inter-individual variability due to the genetic polymorphisms in the warfarin metabolizing enzyme, CYP2C9 and warfarin target, VKORC1. The investigators' team developed a pharmacogenetic dosing algorithm which can predict patients required warfarin dose, thus could prevent warfarin induced warfarin adverse events.
Methods:
The investigators recruited patients with indications for warfarin, the genotypes of VKORC1 and CYP2C9 were determined by the hospitals and verified by National Center for Genome Medicine. The investigators then randomized the patients to one of three arms: 1. Warfarin dose predicted by dosing algorithm developed by the International Warfarin pharmacogenetic Consortium (IWPC), 2. Algorithm developed by the Taiwan Warfarin Consortium and 3. Standard of care. The investigators aimed to determine whether using genetic dosing algorithm can lead to more stable dose and safer use of the drug.

Conditions

Interventions

  • Standard of care dosing for warfarin Behavioral
    ARM 1: Kind: Experimental
    Label: Standard of care dosing for warfarin
    Description: Loading dose (5mg) of warfarin for the first 3 days of treatment. Dose adjustment after initiation will using guideline modified from Tait el al. (1998).
  • Genotype-guided dosingTaiwan algorithm for warfarin Genetic
    ARM 1: Kind: Experimental
    Label: Genotype-guided dosingTaiwan algorithm for warfarin
    Description: Initial loading dosing of warfarin for the first 3 days of treatment will be determined by the Taiwan algorithm that uses clinical and genetic information. Dose adjustment after initiation will using guideline modified from Tait el al. (1998).
  • Genotype-guided dosing IWPC algorithm for warfarin Genetic
    ARM 1: Kind: Experimental
    Label: Genotype-guided dosing IWPC algorithm for warfarin
    Description: Initial loading dosing of warfarin for the first 3 days of treatment will be determined by the IWPC algorithm that uses clinical and genetic information. Dose adjustment after initiation will using guideline modified from Tait el al. (1998).

Trial Design

  • Allocation: Randomized
  • Masking: Double Blind (Subject, Caregiver, Outcomes Assessor)
  • Purpose: Treatment
  • Endpoint: Safety/Efficacy Study
  • Intervention: Parallel Assignment

Outcomes

Type Measure Time Frame Safety Issue
Primary Time spent in target INR range first month of therapy Yes

Sponsors