A study of the effects of manidipine on the diurnal variation of arterial pressure and hemodynamics in patients with essential hypertension.

In order to investigate the effects of manidipine, a newly developed long-acting calcium antagonist, on the diurnal variation of arterial pressure and systemic hemodynamics in patients with essential hypertension, we examined 24-h arterial pressure using a direct arterial pressure monitoring method and cardiac output using the cuvette method before and during manidipine treatment. Once-a-day administration of manidipine at daily doses of 10 to 40 mg decreased systolic and diastolic arterial pressures at almost all measurement points. The arterial pressure reductions were not significantly different between daytime and nighttime. Arterial pressure variability expressed in terms of the standard deviation of values was not affected by manidipine treatment. Thus, it appears that patients treated with manidipine can avoid the excessive decrease in arterial pressure during nighttime that may occur with the use of some other calcium antagonists. Heart rate and its variability were unaffected by manidipine treatment. A hemodynamic study revealed that manidipine did not change cardiac output, but significantly decreased total peripheral vascular resistance at rest. It is concluded that once-a-day administration of manidipine at daily doses of 10 to 40 mg brings about a safe and stable antihypertensive effect over a 24-h period, without affecting the diurnal variation of arterial pressure and heart rate. Dilation of the resistance vessels underlies the antihypertensive effect of the agent.