The acute haemodynamic effects of oral nicardipine.

The haemodynamic effects of oral nicardipine at two different doses were assessed in fifteen patients at rest following diagnostic cardiac catheterisation. Six patients received four doses of 20 mg nicardipine hydrochloride orally every 8 h, and nine patients received four doses of 30 mg orally every 8 h. No side effects were encountered with either dose. At both dose levels, there was a significant fall in systemic vascular resistance, significant increases in heart rate and cardiac output, and no change in stroke volume index. No changes were seen in pulmonary vascular haemodynamics, and there were no significant changes in mean arterial pressure. Plasma levels of nicardipine reached a peak within 1 h. In parallel with the haemodynamic effects, the plasma concentrations achieved after the third and fourth doses were higher than after the first dose. These haemodynamic changes are consistent with a vasodilator effect, which produces a decrease in peripheral vascular resistance. It would appear that the 30 mg dose has a more potent vasodilator action than the 20 mg dose and, in the patients studied, this larger dose was not associated with any side effects.