Combined therapy with benazepril and amlodipine in the treatment of hypertension inadequately controlled by an ACE inhibitor alone

In a multicenter, randomized, double-blind, placebo-controlled study, we evaluated the efficacy and tolerability of the combination of benazepril, 10 mg, and amlodipine, 2.5 or 5 mg once daily, compared with benazepril, 10 mg, monotherapy in patients with hypertension inadequately controlled with angiotensin-converting enzyme (ACE)-inhibitor monotherapy. After a 2-week placebo and 4-week single-blind benazepril, 10 mg once daily, run-in period, 448 patients, 213 men and 235 women, aged 24-73 years (mean, 55 years), with mean diastolic blood pressure (DBP) greater than or equal to 95 and less than or equal to 120 mm Hg at the end of the benazepril run-in period, were randomized to receive one of the following treatments once daily for 8 weeks: (a) benazepril, 10 mg, plus placebo (BZ10); (b) benazepril, 10 mg, plus amlodipine, 2.5 mg (BZ10/AML2.5); or (c) benazepril, 10 mg, plus amlodipine, 5 mg (BZ10/AML5). Before the patients were admitted to the trial, at the end of the placebo run-in and the benazepril run-in period and at the end of weeks 4 and 8 of the treatment period, sitting and standing blood pressure (BP), heart rate (HR), and body weight were measured 22-26 h after the intake of the trial medication. Both BZ10/AML2.5 and BZ10/AML5 combinations showed better antihypertensive activity than did BZ10 monotherapy at the terminal visit as demonstrated by (a) the 24-h postdosing sitting and standing systolic BP (SEP) and DBP values, which were statistically lower with combination therapy than with BZ10; (b) the success rate, which was statistically higher with both the combinations (69.2% in the BZ10/AML2.5 and 65.8% in the BZ10/AML5 group) compared with the BZ10 group (40.5%). The tolerability was good in the three treatment groups. No significant abnormal laboratory data were detected. There was no difference in efficacy and safety/tolerability between the BZ10/AML2.5 and BZ10/AML5 groups.