The Ecology of Antihypertensives in the United States, 1997-2017
AbstractBackgroundAntihypertensives are the most used medication type in the United States, yet there remains uncertainty about the use of different antihypertensives. We sought to characterize use of antihypertensives by and within medication class(es) between 1997-2017.MethodsA repeated cross-sectional study of 493,596 adult individuals using the 1997-2017 Medical Expenditure Panel Survey (MEPS). The Orange Book and published research were used for adjunctive information. The primary outcome was the estimated use by and within anti-hypertensive medication class(es).ResultsThe proportion of individuals taking any antihypertensive during a year increased from 1997 to the early 2010’s and then remained stable. The proportion of the population taking 2 or more medications declined from 2015-2017. The proportion of adults using angiotensin II receptor-blockers (ARBs) and dihydropyridine calcium channel-blockers (CCBs) increased during the study period, while angiotensin-converting enzyme inhibitors (ACE-Is) increased until 2010 after which rates remained stable. Beta-blocker use was similar to ACE-Is with an earlier decline starting in 2012. Thiazide diuretic use increased from 1997-2007, leveled off until 2014, and declined from 2015-2017. Non-dihydropyridine CCBs use declined throughout the study. ACE-Is, ARBs, CCBs, thiazide diuretics, and loop diuretics all had one dominant in-class medication. There was a clear increase in the use of losartan within ARBs, lisinopril within ACE-Is, and amlodipine within CCBs following generic conversion. Furosemide and hydrochlorothiazide started with and maintained a dominant position in their classes. Metoprolol use increased throughout the study and became the dominant beta-blocker, while atenolol peaked around 2005 and then declined thereafter.ConclusionsAntihypertensive classes appear to have a propensity to equilibrate to an individual medication, despite a lack of outcomes based research to compare medications within a class. Future research could focus on comparative effectiveness for within-class medications early in the life cycle of therapeutics that are probable to have wide spread use.