A multicenter evaluation of the safety and efficacy of isradipine and atenolol in the treatment of hypertension. Isradipine in Hypertension Study Group.

A total of 152 patients with essential hypertension (World Health Organization classification I/II) entered a multicenter randomized study to assess the safety and efficacy of isradipine compared with, and in combination with, the beta-blocker atenolol. After a three-week placebo treatment period, patients received either isradipine (2.5, 5, 7.5, or 10 mg twice daily) or atenolol (50 or 100 mg once daily) for seven weeks. Patients who did not have an adequate response (diastolic blood pressure less than 90 mm Hg) with the maximal doses of single-drug therapy were given a combination of both drugs for a further seven weeks. Both drugs resulted in significant and clinically relevant reductions in blood pressures. Although the reduction in diastolic blood pressure was the same for patients receiving the two drugs, there was a statistically significant greater reduction in systolic blood pressure in the isradipine group, suggesting that this drug has a more favorable effect on vascular impedance. Of the 14 patients who did not attain normal blood pressure levels (sitting diastolic blood pressure less than 90 mm Hg) receiving monotherapy, 12 patients reached this goal with a combination of the two drugs.