The effects of high-dose amlodipine/benazepril combination therapies on blood pressure reduction in patients not adequately controlled with amlodipine monotherapy

Background. This study compared the efficacy and safety of amlodipine/benazepril ( 10/40 mg/day and 10/20 mg/day) with amlodipine 10 mg/day in patients whose blood pressure ( BP) was not adequately controlled with amlodipine monotherapy. Methods. After a lead-in period with amlodipine monotherapy, 812 non-responder patients ( mean sitting diastolic BP >= 95 mmHg) were randomized to one of three treatment groups. Ambulatory BP monitoring was conducted in 276 patients. Results. Treatment with amlodipine/benazepril 10/40 mg/day and 10/20 mg/day resulted in a decrease of mean sitting systolic and mean sitting diastolic BP by 13.3/12.7 mmHg and 12.1/11.6 mmHg, respectively, compared with monotherapy ( 6.6/8.5 mmHg) ( p<0.0001). Both combinations resulted in more responders than monotherapy ( 74% and 65% vs. 54%; p<0.0001 and p<0.0085, respectively). Amlodipine/benazepril 10/40 mg/day and 10/20 mg/day decreased ambulatory systolic and diastolic BP by 9.9/6.7 mmHg and 7.4/5.2 mmHg compared with monotherapy ( p<0.0001). The incidence of pedal edema was lower in the amlodipine/benazepril combinations compared with monotherapy ( 4.5%, 5.5% vs. 9.2%, respectively, p=NS). No significant metabolic side-effects were noted among the combination groups. Conclusion. Amlodipine/benazepril combinations were well tolerated and resulted in significant BP reductions and better BP responder rates than amlodipine monotherapy.