Isotonic and Isometric Responses of Blood Pressure and Heart Rate in Mild to Moderate Hypertension with Isradipine and Propranolol

Abstract

The objectives of this study were (a) to evaluate the dose-response effect of isradipine, a dihydropyridine calcium antagonist, on the heart rate and blood pressure of males with mild to moderate hypertension; and (b) to compare these results with those obtained with propranolol, a beta-adrenoceptor blocker, on a matched patient population. Twenty-four patients entered a single-blind study, beginning with a 2-week washout placebo period followed by a forced-titration period. Treadmill and hand-grip tests were also performed. Two weeks were allocated to each stage of the therapy. The end point of the study was normalization of blood pressure with a minimum of side effects. Results and conclusions include the following: both drugs were effective in reducing systolic blood pressure (SBP) and diastolic blood pressure (DBP), but isradipine was more effective in reducing the DBP; isometric exercise can predict accurately the results of the isotonic exercise; the maximum therapeutic effect of propranolol was achieved during the second study-dose level; increases in the isradipine dose were reflected in a proportional reduction of SBP and DBP; and the incidence of side effects is lower among isradipine-treated patients compared to propranolol-treated patients.