Figure 1. . The CPIC (2017) Dosing Recommendations for Warfarin Dosing based on Genotype for Adult Patients.

Figure 1.

The CPIC (2017) Dosing Recommendations for Warfarin Dosing based on Genotype for Adult Patients. (a) “Dose clinically” means to dose without genetic information, which may include use of a clinical dosing algorithm or standard dose approach. (b) Data strongest for European and East Asian ancestry populations and consistent in other populations. (c) 45–50% of individuals with self‐reported African ancestry carry CYP2C9*5, *6, *8, *11, or rs12777823. If CYP2C9*5, *6, *8, and *11 were not tested, dose warfarin clinically. Note: these data derive primarily from African-Americans, who are largely from West Africa. It is unknown if the same associations are present for those from other parts of Africa. (d) Most algorithms are developed for the target INR 2‐3. (e) Consider an alternative agent in individuals with genotypes associated with CYP2C9 poor metabolism (e.g., CYP2C9*3/*3, *2/*3, *3/*3) or both increased sensitivity (VKORC1 A/G or A/A) and CYP2C9 poor metabolism. (f) See the EU‐PACT trial for pharmacogenetics‐based warfarin initiation (loading) dose algorithm with the caveat that the loading dose algorithm has not been specifically tested or validated in populations of African ancestry. (g) Larger dose reduction might be needed in variant homozygotes (i.e., 20–40%). (h) African-American refers to individuals mainly originating from West Africa.
This figure is adapted from (4). Please see Therapeutic Recommendations based on Genotype for more information from CPIC.

From: Warfarin Therapy and VKORC1 and CYP Genotype

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