Abstract
This study investigated the effects of a low dose of nisoldipine (5mg, p.o.) in 10 patients with ischemic heart disease. The patients were subjected to a 90-min exercise regimen before and after a 5mg dose of nisoldipine, using a supine bicycle ergometer adjusted to each patient's limitations. The mean blood plasma level of nisoldipine was 3.8±3.1 (SD) ng/ml. The drug significantly decreased the systolic arterial pressure in patients throughout the experimental session, whereas a change in the diastolic arterial pressure appeared only at the submaximal stage of the exercise. Additionally, at maximal exercise, nisoldipine caused a decrease in the mean coronary sinus pressure from 11.4±7mmHg to 6.5±5mmHg (p<0.01). By contrast, while at rest, nisoldipine decreased the coronary vascular resistance from 1.5±0.7mmHg/ml/min to 1.0±0.7mmHg/ml/min (p<0.05). After exercise, the drug decreased thromboxane B2 levels from 1133±907pg/ml to 720±379pg/ml (p<0.05) in the coronary sinus blood, and increased the 6 keto-prostaglandin F1α levels from 465±135pg/ml to 559±167pg/ml (p<0.05) in brachial artery blood. This suggests that a low, oral dose of nisoldipine can moderately improve the systemic and coronary hemodynamics and afterloads, and may assist in improving the prostaglandin metabolism in ischemic heart disease patients.
