Characteristics, drug combinations and dosages of primary care patients with uncontrolled ambulatory blood pressure and high medication adherence

Abstract

Most studies on the prevalence and determinants of resistant hypertension (RH) do not account for white coat hypertension, medication non-adherence, or use of suboptimal treatment dosages. We studied the characteristics, drug combinations, and dosages of patients on at least three antihypertensives of different classes who had uncontrolled blood pressure on 24-hour ambulatory blood pressure monitoring and high medication adherence measured by electronic monitoring. The data were collected as part of the baseline measures of a hypertension control trial. Of 140 monitored primary care patients, all with uncontrolled office blood pressure, 69 (49%) were on at least three antihypertensives of different classes. Of these 69, 15 (22%) were controlled on ambulatory blood pressure monitoring, 20 (29%) were uncontrolled and non-adherent, leaving only 34 (49%) adherent to their medications and having uncontrolled ambulatory hypertension (uncontrolled RH). Thirty-one (91%) of the 34 uncontrolled RH patients were prescribed a diuretic, of which 24 were on hydrochlorothiazide 25 mg. Less than half of the patients on angiotensin-converting enzyme inhibitor, angiotensin receptor blocker, or calcium channel blocker were prescribed maximal doses of these agents. Half of the RH can be attributed to white coat effect and poor medication adherence, and all of the remaining patients were on apparently suboptimal drug combinations and/or dosages. Primary care physicians need to be educated regarding the optimal treatment of RH.

Keywords: Resistant hypertension; drug dosage; electronic monitoring; medication adherence; white-coat hypertension.

Conflict of interest statement

No conflict of interests to declare.

Copyright © 2013 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

Figures

Figure 1

Flow chart describing patient selection for analyses. ABPM, Ambulatory blood pressure monitoring; MEMS, Medication Event Monitoring System.

Figure 2

Drug combinations of 34 patients with uncontrolled resistant hypertension. aIncluding eight patients on diuretic/ACEi/β-blocker; two on diuretic/ARB/β-blocker; one on diuretic/CCB/β-blocker; one on ACEi/CCB/β-blocker; and one on ARB/β-blocker/direct vasodilator. bIncluding eight patients on a three-drug combination of diuretic/ACEi/CCB; two on four-drug combination of diuretic/ACEi/CCB/β-blocker; and two on a five-drug combination of diuretic/ACEi/CCB/β-blocker/α2-agonist. cIncluding one patient on a three-drug combination of diuretic/ARB/CCB; two on a four-drug combination of diuretic/ARB/CCB/β-blocker; and one on diuretic/ARB/CCB/ACEi/β-blocker. dIncluding two patients on diuretic/ACEi/ARB/β-blocker; one on diuretic/CCB/β-blocker/α2-agonist; and one on diuretic/ACEi/β-blocker/α2-agonist. ACEi, Angiotension-converting enzyme inhibitor; ARB, angiotensin receptor blocker; CCB, calcium-channel blocker.