AMLODIPINE - ONCE-DAILY MONOTHERAPY IN SYSTEMIC HYPERTENSION

Amlodipine is one of the second-generation calcium antagonists. It is chemically similar to the prototype drug nifedipine and another 1,4 dihydropyridine calcium antagonist.1 However, amlodipine has a distinct pharmacodynamic profile, processing slow onset of action, high bioavailability and a prolonged plasma half-life of 35 to 48 hours.2,3 Previous studies with amlodipine showed that it reduced systemic vascular resistance and systemic arterial pressure.4-4 The low total body clearance and long plasma half-life of amlodipine make it theoretically suitable for 24-hour control of blood pressure (BP) with a single dose.6-8 This drug is available for prescription in about 22 countries worldwide, and has been approved by the U.S. Food and Drug Administration. However, whether amlodipine can control the efficacy of BP 48 hours after administration still remains unknown. This study assesses the 48-hour efficacy of amlodipine administered as once-daily monotherapy for mild to moderate hypertension using noninvasive ambulatory BP monitoring in ambulant patients. Changes in BP and heart rate in response to various physiologic tests were also studied. © 1994.