Evaluation of the antihypertensive effect of amlodipine using 24-hour ambulatory blood pressure measurement

The antihypertensive effect of amlodipine was investigated in 20 patients (11 men and nine women) with essential hypertension using 24-hour monitoring of ambulatory blood pressure. The patients received placebo initially for 1 week followed by amlodipine 5 mg/day for 8 weeks. In three patients whose diastolic blood pressure did not fall below 90 mmHg after 4 weeks, the dosage was raised to 10 mg/day. All patients underwent ambulatory blood pressure monitoring at the end of the placebo period and at the end of 8 weeks of active treatment. Blood pressures and heart rate were measured and a physical examination was performed every 2 weeks during the treatment period. By the second week of treatment, systolic and diastolic blood pressures were significantly reduced with amlodipine therapy (P 0.01). The reduction was more pronounced in the fourth week (P 0.001). There were no significant changes in heart rate. Ambulatory investigations revealed a significant decrease in both systolic and diastolic blood pressures every hour of the day (P 0.001). On the other hand, heart rate was significantly reduced only between 8 am and 12 noon (P 0.05). Changes at other hours of the day were not significant. Drug-related side effects disappeared quickly without the need for tapering off or discontinuing the drug. Amlodipine is an effective and well-tolerated drug for the treatment of hypertension. © 1993 Excerpta Medica, Inc. All rights reserved