Effect of CYP2C9-VKORC1 interaction on warfarin stable dosage and its predictive algorithm

Area of Science:

• Pharmacogenomics
• Clinical Pharmacology
• Drug Metabolism

Background:

• Warfarin dosage is influenced by genetic factors, including variations in CYP2C9 and VKORC1 genes.
• Understanding gene-drug interactions is crucial for optimizing warfarin therapy and minimizing adverse events.

Purpose of the Study:

• To investigate the impact of the CYP2C9-VKORC1 gene interaction on warfarin dosage requirements.
• To evaluate the effect of this interaction on the accuracy of predictive algorithms for warfarin stable dosage (WSD).

Main Methods:

• Analysis of four distinct populations to assess warfarin stable dosage (WSD).
• Utilized generalized linear models to examine the relationship between CYP2C9-VKORC1 interaction and WSD.
• Employed multiple linear regression to develop and compare WSD predictive algorithms, with and without considering the gene interaction.

Main Results:

• The CYP2C9-VKORC1 interaction showed a significant association with WSD in Chinese and White cohorts (P < 0.05).
• Predictive algorithms incorporating the CYP2C9-VKORC1 interaction demonstrated only marginal improvements in predictive success rates (0.12% in Chinese, 0.02% in White patients).
• The discrepancies in predictive results between algorithms with and without the interaction were negligible.

Conclusions:

• While the CYP2C9-VKORC1 interaction influences warfarin stable dosage, its inclusion in predictive algorithms yields minimal enhancement in accuracy.
• The negligible impact suggests that current predictive models may not significantly benefit from explicitly incorporating this specific gene interaction for warfarin dosing.