Fixed-dose combination vs monotherapy in hypertension: a meta-analysis evaluation

Abstract

Fixed-dose combination antihypertensive therapy has received interest since the publication of the JNC-VI report. Relatively few head-to-head comparative studies between fixed-dose combinations and first-line monotherapies for hypertension have been published. The objective of this study was to conduct a meta-analysis of various first-line monotherapies and the fixed-dose combination of amlodipine/benazepril. The results of the meta-analysis were used to compare the efficacy and safety of the first-line monotherapies with amlo- dipine/benazepril. The meta-analysis included 82 studies that included 110 treatment groups (cohorts). The study compared nine different monotherapies and one combination therapy (amlodipine/benazepril). Of the 82 studies, 22 were placebo-controlled and 60 were active treatment controlled. The mean absolute decrease in supine diastolic blood pressure (BP) ranged from 9.7 to 13.3 mm Hg with verapamil showing the greatest effect and captopril the least (13.3 ± 3.0 mm Hg; 9.7 ± 2.9 mm Hg, respectively). When studies were weighted by sample size, atenolol, verapamil, lisinopril and amlo- dipine/benazepril showed the greatest BP effect. When studies were weighted by variance, amlo- dipine/benazepril and atenolol showed the greatest BP effect. The percentage of patients controlled on therapy ranged from 54% to 79% Lisinopril and amlodipine/benazepril showed the greatest percent controlled. The overall incidence of adverse effects ranged from 12.1% to 41.8% with lisinopril having the lowest and nifedipine having the highest incidence. The overall incidence of adverse effects resulting in drug discontinuance ranged from 1.3% to 10.7%, with amlodipine/benazepril having the lowest and nifedipine having the highest incidence. The results of the meta-analysis indicate that amlodipine/benazepril produces above average reductions in BP with a lower than average incidence of overall side effects and the lowest incidence of adverse effects resulting in drug discontinuance. The fixed-dose combination of amlodipine/ benazepril achieves its goal of effective BP lowering with a minimum of significant side effects.