Azelnidipine and Amlodipine: A Comparison of Their Effects and Safety in a Randomized Double-Blinded Clinical Trial in Chinese Essential Hypertensive Patients

The purpose of this study is to compare the effects and safety of azelnidipine and amlodipine in Chinese essential hypertensive patients. Patients were randomized to receive administration of azelnidipine 8-16 mg/day or amlodipine 2.5-5 mg/day for 8 weeks. The blood pressure and pulse rate were evaluated in an outpatient clinic and by ambulatory blood pressure monitoring. There were 220 patients enrolled to the study. The blood pressure in both groups was decreased significantly (P < 0.001). Compared with amlodipine, the patients received azelnidipine had better response in systolic blood pressure (SBP) and diastolic blood pressure (DBP) (P < 0.01). No significant changes of pulse rate were observed in either group. For the ambulatory blood pressure monitoring, both drugs had stable anti-hypertensive effects over 24 h. The trough/peak ratios of DBP for the azelnidipine and amlodipine groups were, respectively, 46% and 40%. Adverse events occurred at 7.3% and 10.0%, respectively in the azelnidipine and amlodipine groups (P = 0.485). Headache and dizziness were observed at an incidence of more than 1% in both groups. Once-daily administration of azelnidipine effectively controlled blood pressure and had a stable action over 24 h. Azelnidipine had good safety and compliance similar to amlodipine.