Role of Preemptive Genotyping in Preventing Serious Adverse Drug Events in South Korean Patients.

Introduction: Preemptive and multi-variant genotyping is suggested to improve the safety of patient drug therapy. The number of South Koreans who would benefit from this approach is unknown.

Objective: We aimed to quantify the number of patients who may experience serious adverse drug events (ADEs) due to high-risk pharmacogenetic variants and who may benefit from preemptive genotyping.

Methods: The health claims dataset of the Korean Health Insurance Review and Assessment service for 3 % of the South Korean population for year 2011 was used to calculate the number of patients exposed to 84 drugs covered by National Health Insurance with pharmacogenomic biomarkers. The product of ADE risk-conferring genotype prevalence, ADE prevalence rates, and genotype effect sizes in South Koreans or East Asians derived from published literature and the 1000 Genomes Project, and the drug exposure data were solved to estimate the number of South Koreans in whom preemptive genotyping may prevent serious ADEs.

Results: Among 1,341,077 patients in the dataset with prescriptions, 47.4 % were prescribed a drug whose response was affected by genetic variants and 31.9 % were prescribed at least one drug with serious ADEs modulated by these variants. Without genetic testing, the number of South Korean patients predicted to experience serious ADEs due to their higher ADE risk genotypes was estimated at 729. Extrapolating this to the total South Korean population indicated that approximately 24,300 patients in 2011 might have benefitted from preemptive genotyping.

Conclusions: This study quantified the number of South Korean patients predicted to have serious ADEs and demonstrated the need for preemptive genotyping to assist safer drug therapy in South Korea.