The Ecology of Antihypertensives in the United States, 1997–2017

Antihypertensives are the most used medication type in the USA, 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 and 2017.

A repeated cross-sectional study of 493,596 adult individuals using the 1997–2017 Medical Expenditure Panel Survey (MEPS). The Orange Book was used for adjunctive information. The primary outcome was the estimated use by and within antihypertensive medication class(es).

The proportion of individuals taking any antihypertensive during a year increased from 1997 to the early 2010s and then remained stable. 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 that of ACE-Is with an earlier decline starting in 2012. Thiazide diuretic use increased from 1997 to 2007, leveled off until 2014, and declined from 2015 to 2017. Non-dihydropyridine CCB 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.

Antihypertensive 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.