Background: Antihypertensive medication use patterns have likely been influenced by changing costs and accessibility over the past 3 decades. This study examines the relationships between patent exclusivity loss, medication costs, and national health policies on antihypertensive medication use.
Methods: Using 1996 to 2021 Medical Expenditure Panel Survey data of US adults with hypertension taking at least 1 antihypertensive medication, we conducted a cross-sectional analysis. We explored the associations between patent exclusivity loss, per-pill costs, and Medicare Part D enactment on medication use over time, focusing on the most commonly used medications (lisinopril, amlodipine, losartan, hydrochlorothiazide, and metoprolol).
Results: The unweighted sample comprised 50 095 US adults (mean age, 62 years; 53% female). The survey-weighted number of adults taking antihypertensive medications increased from 22 million (95% CIs, 20-23 million) to 55 million (95% CI, 51-60 million) between 1996 and 2021. Loss of patent exclusivity led to increased medication fills, notably for lisinopril, amlodipine, and losartan, which all exhibited within-class dominance. However, per-pill cost decreases coinciding with Medicare Part D did not increase the number of individuals treated or the use of specific antihypertensive medications or classes.
Conclusions: The increase in antihypertensive medication use over the past decades highlights the significant impact of loss of patent exclusivity on the uptake in the use of specific medications. These findings underscore the complexity of factors influencing medication use, beyond cost reductions alone, and suggest that policies need to consider multiple facets to effectively improve antihypertensive medication accessibility and utilization.
Keywords: antihypertensive agents; blood pressure; drug industry; drugs, generic; essential hypertension; healthcare costs; medicare part D.