[The effect of rate of administration of isradipine on the hemodynamic response].
Carrara V., Porchet HC., Dayer P.
As the magnitude of drug response may depend on its input rate, we investigated the rate of administration-effect relationship of the new dihydropyridine isradipine. Ten healthy volunteers received (double-blind and cross-over) isradipine 1 mg i.v. (5 min), 5 mg solution, 5 mg tablet, 10 mg sustained release, and placebo. Blood pressure and heart rate were recorded for 24 h. A single dose of slow-release formulation isradipine does not induce significant hemodynamic effects in healthy subjects. The maximal BP fall was comparable with either i.v., solution, and conventional tablet administration. This is due to a stronger heart rate counter-regulation, linked to rapid isradipine administration. These results imply that slow input rates of isradipine are more effective in lowering blood pressure.