Combination therapy of amlodipine/benazepril versus monotherapy of amlodipine in a practice-based setting

Background: Community-based studies are conducted to determine the degree to which therapeutic interventions will succeed in real world settings. This large practice-based clinical trial assessed the efficacy and tolerability of fixed-dose combination therapy with amlodipine/benazepril, compared with amlodipine monotherapy, in patients with mild-to-moderate hypertension. Methods: Hypertensive patients currently taking amlodipine were selected based on one of two criteria: inadequate blood pressure (BP) control on amlodipine (diastolic BP [DBP] greater than or equal to90 mm Hg; group 1), or inability to tolerate amlodipine (DBP less than or equal to90 mm Hg, but with edema; group 2). Eligible patients were switched from 5 or 10 mg of amlodipine to 5110 mg or 5/20 mg of amlodipine/benazepril for 4 weeks. In group I (n = 6410), primary efficacy outcome was change in mean sitting DBP. A secondary efficacy outcome was change in mean sitting systolic BP (SBP). In group 2 (n = 1502), primary efficacy outcome was the percentage of patients whose edema improved during therapy with amlodipine/benazepril when compared with amlodipine monotherapy. Results: In group 1, mean sitting DBP declined from 96.5 mm Hg at baseline to 84.9 mm Hg at week 4, a mean reduction of 11.5 mm Hg (95% confidence interval [CI] - 11.8 to - 11.3 mm Hg; P <.001). From baseline to week 4, mean sitting SBP declined from 152.9 mm Hg to 137.3 mm Hg, a mean reduction of 15.6 mm Hg (95% Cl - 16.0 to - 15.2 mm Hg; P <.001). In (,roup 2, 85% (95% Cl 83%-87%) experienced some improvement in edema compared with baseline levels. Conclusions: Fixed-dose combination antihypertensive agent amlodipine/benazepril was safe and effective for patients who experienced either inadequate BP control or edema with amlodipine monotherapy.