The efficacy and safety of fixed-dose combination of amlodipine/benazepril in Chinese essential hypertensive patients not adequately controlled with benazepril monotherapy: a multicenter, randomized, double-blind, double-dummy, parallel-group clinical trial

This double-blind, double-dummy clinical trial evaluated the efficacy and safety of two strengths of fixed-dose combination of amlodipine/benazepril in Chinese hypertensive patients not adequately controlled with benazepril. Of 442 patients who received treatment with benazepril 10 mg for 4 weeks, 341 patients failed to achieve to diastolic blood pressure (DBP) <90 mmHg. These non-responders were randomized to receive amlodipine/benazepril 2.5/10 mg, or amlodipine/benazepril 5/10 mg, or benazepril 10 mg for 8 weeks. BP reductions with amodipinel/benazepril 2.5/10 mg (15.2/11.8 mmHg) or amlodipine/benazepril 5/10 mg (15.4/12.4 mmHg) were significantly greater than that with benazepril 10 mg (9.88/9.46 mmHg) at study end (p < 0.01, combination versus benazepril). BP control rate was 83.8% with amlodipine/benazepril 2.5/10 mg, 80.2% with amlodipine/benazepril 5/10 mg, 64.9% with benazepril 10 mg at study end (p < 0.01, combination versus benazepril). Three groups were generally well tolerated. Our study indicated that amlodipine/benazepril fixed-dose combination offered significant additional BP reductions and BP control rate compared with the continuation of benazepril monotherapy. No significant differences were observed in both BP reductions and BP control rate between amlodipine/benazepril 2.5/10 mg and amlodipine/benazepril 5/10 mg.