Annotation of DPWG Guideline for warfarin and VKORC1
Summary
Patients with the VKORC1 rs9923231 TT genotype (-1639 AA genotype) should be given 60% of the standard initial dose of warfarin. The genotype-specific initial dose and maintenance dose can be calculated using an algorithm. There are no recommendation for patients with the VKORC1 rs9923231 CT genotype (-1639 AG genotype).
Specify a genotype or phenotype for specific annotations
Alleles not present in the above pull-down menus have no recommendation.
Annotation
Read more about how PharmGKB curates DPWG guidelines using extra information provided by DPWG to enable the interactive genotype tool above.
November 2018 Guideline
The Royal Dutch Pharmacists Association - Pharmacogenetics Working Group (DPWG) has evaluated therapeutic dose recommendations for warfarin based on VKORC1 genotype. They recommend that patients with the VKORC1 rs9923231 TT genotype (-1639 AA genotype) receive 60% of the standard initial dose.The genotype-specific initial dose and maintenance dose can be calculated using an algorithm. No action is needed for patients with the VKORC1 rs9923231 CT genotype (-1639 AG genotype).
Download the warfarin loading doses algorithm used in EU-PACT provided by DPWG this is an excel file retrieved from DPWG on 3/19/2024. Download the warfarin day 4-5 algorithm used in EU-PACT provided by DPWG this is an excel file retrieved from DPWG on 3/20/2024.
Wording in table taken from the Dutch guidelines November 2018 update.
Read for more information about this recommendation, Read about gene information from DPWG