Background: Fixed-dose combinations can simplify prescribing, and numerous combination products exist for hypertension and dyslipidemia in South Korea. This study's aim was to compare trends in the consumption of single products versus fixed-dose combinations for hypertension and hyperlipidemia.
Methods and findings: We analyzed the Korean national health insurance claims database from January 2015 through December 2019. Consumption of medicines was calculated using the defined daily dose per 1,000 inhabitants per day (DIDs) and expenditures over time. During 2015-2019, the use of antihypertensive drugs increased with an annual growth rate (AGR) of 0.9% for single products and with an AGR of 35.6% for fixed-dose combinations. A notable increase was observed for antihyperlipidemic combination drugs with an AGR of 268.1% compared to single products with 35.7%. For older adults (65+ years), the consumption of drugs for hypertension and hyperlipidemia was 3-4.5 and about 3 times higher, respectively, than in adults aged 20-64 years, and a sharp increase was found in antihyperlipidemic fixed-dose combinations among older adults. A large increase was seen for C09 (agents acting on the renin-angiotensin system) with an AGR of 36.5%, especially C09DB (angiotensin II receptor blockers + calcium channel blockers) was widely used and steeply increased with 114.2%. For antihyperlipidemic drugs, C10AA (HMG CoA reductase inhibitors) accounted for a large share and sharply increased, with 52.1 DIDs in 2019 and with an AGR of 78.4%, whereas C10BA (combinations of various lipid modifying agents) increased 9.6 times from 2.9 DIDs (96 million USD) in 2015 to 27.7 DIDs (912 million USD) in 2019.
Conclusion: The findings of increased consumption and drug spending among older adults underscores the need for real-world evidence about health outcomes of fixed-dose combinations in this population.