Efficacy of the calcium antagonist isradipine in angina pectoris

Summary Thirty-six patients with chronic, stable angina pectoris were studied during 2-week treatment periods in which they received, in a randomized double-blind, crossover study, a new calcium entry blocking agent, isradipine, 7.5 mg three times daily or placebo. Antianginal efficacy was determined by treadmill exercise testing carried out 3 and 9 hours after drug administration on the final day of each treatment period. During placebo therapy, treadmill exercise time to the onset of angina (P₁) and to the development of moderate angina (P₂) was similar at 3 and 9 hours and similar to the placebo run-in period. During isradipine therapy, treadmill exercise time 3 hours after dosing was greater than with placebo therapy (P₁ 312±23.0 vs. 267±19.5 seconds,p<0.001; P₂ 410±20.2 vs. 355±18.8 seconds,p<0.002). Nine hours after drug administration, the results of exercise testing were similar to placebo.