High-dose monotherapy vs low-dose combination therapy of calcium channel blockers and angiotensin receptor blockers in mild to moderate hypertension

Abstract

The objectives of the study were to compare long-acting dihydropyridine calcium channel blockers (CCBs) with angiotensin II receptor blockers (ARBs) according to the ambulatory blood pressure monitoring (ABPM) profile in stage 1 and 2 newly diagnosed hypertensives and also to evaluate the efficacy of high-dose monotherapy vs low-dose combination therapy of the two drug categories among the subjects with inadequate blood pressure (BP) control after conventional low-dose monotherapy. We obtained 24-h ABPM readings from 302 subjects with newly diagnosed stage 1 or 2 essential hypertension. The study protocol consisted of initial drug treatment with a low dose of either CCBs or ARBs. Hypertensives who did not achieve BP control were randomized to high-dose monotherapy of either category of drug or low-dose combination therapy. CCBs and ARBs in low-dose monotherapy achieved BP control in 53.8 and 55.3% of the cases, respectively. However, subjects under treatment with CCBs experienced side effects more often and required that treatment be discontinued. Hypertensives who failed to control their BP with low-dose monotherapy did significantly better with low-dose combination treatment (61.6%) than with high-dose CCBs (42.8%) or ARBs (40.5%) monotherapy (P<0.05). In terms of ABPM, low-dose combination therapy exhibited better 24-h BP profile according to trough-to-peak ratio, hypertensive burden and BP variability. In conclusion, low-dose ARBs and CCBs have a comparable effect in subjects with grade 1 and 2 arterial hypertension. In hypertensives who are not controlled by low-dose monotherapy, low-dose combination therapy proves be more efficacious than high-dose monotherapy.