Peripheral vascular effects of calcium entry blockers in normal volunteers

The peripheral vascular effects of calcium entry blockers have been scarcely investigated. Therefore we examined the effects of different doses of tiapamil and nifedipine in two groups of volunteers. The measurements were done by plethysmography. At a lower dose there is a significant increase in venous capacity. At a higher dosage there is an increase of the arterial flow, eliciting a reflex sympathetic stimulation with heart rate increase and venoconstriction. Therefore calcium entry blockers can be considered as arterial and venodilators.