Americans are using more antihypertensive drugs, and more drugs in combination, a trend that is paying off with better control of hypertension.
In the first decade of the 21st century the number of patients using multiple agents jumped from 36.8% in 2001 to 47.7% in 2010 (P<0.01), according to Qiuping Gu, MD, PhD, of the CDC's National Center for Health Statistics in Hyattsville, Md., and colleagues.
Compared with monotherapy, single-pill combinations and multiple-pill combinations were associated with 55% and 26% relative increases, respectively, in the likelihood of achieving blood pressure control (P<0.05 for both), the researchers reported online in Circulation: Journal of the American Heart Association.
“The value of using multiple antihypertensive drugs [is that it] improves the overall efficacy of drugs, reduces dose-dependent side effects, and increases patients’ adherence to medication regimens,” the authors wrote.
Gu and colleagues analyzed data on 9,320 adults with hypertension who participated in one of the National Health and Nutrition Examination Survey (NHANES) cycles from 2001 to 2010, covering years both before and after publication of the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) in 2003.
Hypertension was defined as a systolic blood pressure of 140 mm Hg or higher, a diastolic pressure of 90 mm Hg or higher, or an answer of yes to the question, “Because of your hypertension/high blood pressure are you now taking prescribed medicine?”
Blood pressure control was defined as a systolic blood pressure of less than 130 mm Hg and a diastolic pressure of less than 80 mm Hg for patients with diabetes or chronic kidney disease or a systolic pressure of less than 140 mm Hg and a diastolic pressure of less than 90 mm Hg for others.
Overall, the rate of antihypertensive medication use increased from 63.5% in 2001-2002 to 77.3% in 2009-2010 (P<0.01), primarily attributed to an increase in the percentage of patients taking more than one medication. Use of thiazide diuretics, beta-blockers, ACE inhibitors, and angiotensin receptor blockers increased by a relative 23%, 57%, 31%, and 100%, respectively, whereas use of calcium channel blockers remained relatively steady. The rate of hypertension control increased overall (28.7% to 47.2%, P<0.01) and among those patients who were taking medications (44.6% to 60.3%, P<0.01). Although the overall trends were positive, certain disparities remained at the end of the study period. Mexican Americans, for example, had lower rates of medication use and blood pressure control, which has been seen historically. "Their being less likely to be prescribed medicine when hypertension is present, their higher reliance on monotherapy when medicine is prescribed, and their nonpersistence with prescribed medication regimens may all contribute to the inadequate blood pressure control seen among Mexican Americans," the authors wrote. In addition, older patients were more likely to use medications, but less likely to achieve blood pressure control compared with their younger counterparts. And finally, treated but uncontrolled hypertension was more common among those with diabetes and chronic kidney disease. "More efforts are needed to close the gap between treatment and control and to maximize the public health and clinical benefits among those high-risk subpopulations," the authors wrote. They acknowledged that the findings may have been influenced by the definition of medication users as those who had used a drug in the month before the survey; those who had used an antihypertensive more than a month before the survey were considered nonusers. Also, blood pressure measurements in NHANES were performed at a single time point, possibly resulting in misclassification of hypertension status.
Primary source: Circulation: Journal of the American Heart Association
Source reference: Gu Q, et al “Trends in antihypertensive medication use and blood pressure control among United States adults with hypertension: the National Health and Nutrition Examination Survey, 2001 to 2010” Circulation 2012; DOI: 10.1161/CIRCULATIONAHA.112.096156.