Comparison of antihypertensive effects of an angiotensin-converting enzyme inhibitor, a calcium antagonist and a diuretic in patients with hypertension not controlled by angiotensin receptor blocker monotherapy.

Author(s): Stergiou GS, Makris T, Papavasiliou M, Efstathiou S, Manolis A

Affiliation(s): Hypertension Centre, Third University Department of Medicine, Sotiria Hospital, Athens, Greece. gstergi@med.uoa.gr

Publication date & source: 2005-04, J Hypertens., 23(4):883-9.

Publication type: Clinical Trial; Randomized Controlled Trial

OBJECTIVE: To compare the additional antihypertensive effects of an angiotensin-converting enzyme inhibitor (ACEI), a dihydropyridine calcium antagonist and a diuretic in patients whose hypertension is not controlled by full-dose angiotensin receptor blocker (ARB) monotherapy. DESIGN AND METHODS: Individuals with an ambulatory blood pressure (ABP) that was not controlled by valsartan 160 mg once daily were allocated randomly to two groups: those in group A (n = 35) were assigned randomly to treatment with benazepril 20 mg once daily or chlorthalidone 12.5 mg once daily, whereas patients in group B (n = 29) were assigned randomly to benazepril 20 mg once daily or amlodipine 5 mg once daily. All individuals continued to receive background valsartan 160 mg once daily. After 5 weeks, patients crossed over to the alternative valsartan-based combination treatment of each group for a second 5-week period. Twenty-four-hour ABP monitoring was performed before the random allocation to groups and at the end of each randomized combination pharmacotherapy period. RESULTS: Sixty-four individuals completed the study: 32 men and 32 women (mean +/- SD age 48.2 +/- 7.9 years, average 24-h ABP on valsartan monotherapy 143.4 +/- 12.6/87.7 +/- 7.8 mmHg). Significant additional antihypertensive effects on the average 24-h ABP were obtained with benazepril (8.6 +/- 8.8/6.3 +/- 6.7 mmHg), amlodipine (15.2 +/- 12.9/9.9 +/- 6.8 mmHg) and chlorthalidone (13.5 +/- 11.6/9.5 +/- 7.7 mmHg) (P < 0.001 for all additional antihypertensive effects). The additional effects of amlodipine and chlorthalidone added to valsartan were approximately 6/3.5 mmHg (P < 0.05) greater than that of benazepril. CONCLUSIONS: In patients in whom hypertension was not controlled by full-dose ARB monotherapy, a diuretic, a calcium antagonist or an ACE inhibitor provided significant additional antihypertensive effect. The antihypertensive effects of the ARB-diuretic and the ARB-calcium antagonist combinations were superior to that of the ARB-ACE inhibitor combination.