[Hemodynamic effects of the new calcium antagonist nimodipine in normal and increased blood pressure].

The new compound nimodipine, a calcium channel-blocking agent, belongs to the dihydropyridine derivatives. In experimental studies it exhibits a preferential vasodilator action on cerebral vascular smooth muscle. We studied the hemodynamic effects of nimodipine in 8 normotensives (5 male, 3 female, mean age 47.8 +/- 3.7 years) and 8 patients (6 male, 2 female, mean age 57.4 +/- 2.6 years) with a systolic blood pressure greater than or equal to 165 mm Hg. After administration of nimodipine in hourly increasing doses of 0.015 mg/kg/h, 0.030 mg/kg/h and 0.045 mg/kg/h by an i.v. infusion, the following parameters were measured continuously: systolic, diastolic and mean arterial pressure (brachial artery), systolic and diastolic pulmonary artery pressure, pulmonary wedge pressure, cardiac and stroke volume index, total vascular resistance, stroke work index, blood flow in the legs by venous occlusion plethysmography and heart rate. Nimodipine provided a significant reduction of systolic, diastolic and mean arterial blood pressures when 0.015 and 0.030 mg/kg/h were infused. The higher dose of 0.045 mg/kg/h did not reduce these values any further. In normotensives cardiac index increased significantly. Hardly any changes in heart rate were observed. Total vascular resistance decreased significantly. Preload remained nearly unchanged. From these results it is concluded that the new calcium antagonist nimodipine provides potent vasodilator effects with a moderate reduction of blood pressure and without significant changes in heart rate.