Systemic and arterial hemodynamic effects of nifedipine (20 mg) in mild-to-moderate hypertension.

Systemic and arterial hemodynamic effects of the new 20 mg tablet of nifedipine were studied in seven patients with mild-to-moderate essential hypertension. Hemodynamics of the forearm arterial circulation were investigated using a new pulsed Doppler system, enabling the simultaneous determination of the brachial artery diameter and the arterial blood flow velocity. After nifedipine administration, blood pressure decreased significantly, due to a fall in total peripheral resistance. Simultaneously, brachial blood flow increased significantly, due both to an increase in arterial diameter and blood flow velocity. The study provided evidence that, with nifedipine, there is both 1) a dilation of small arteries, causing a decrease in blood pressure; and 2) a dilation of peripheral large arteries, leading to an increase in peripheral blood flow.