The effects of cyclosidimine, a peripheral vasodilator drug, on blood pressure and heart rate in healthy subjects.

Cyclosidimine is a new vasodilator drug with a direct action on vascular smooth muscle. Oral administration of 2.5, 5.0 and 7.5 mg in five normal volunteers had no effect on blood pressure in the supine position but reduced systolic and diastolic pressure in the erect position. In both positions heart rate was significantly greater after cyclosidimine than after placebo. Propranolol prevented the increases in heart rate produced by cyclosidimine which then produced greater reductions in blood pressure.