Verapamil therapy for stable exertional angina pectoris.

Clinical and exercise responses to therapy with the calcium-channel blocking agent verapamil were assessed in 26 patients with stable exertional angina pectoris using a double-blind, placebo-controlled, randomized crossover study design. Verapamil, 480 mg daily, reduced the frequency of angina attacks (5.6 +/- 7.3 to 2.2 +/- 3.0 attacks per week, p less than 0.001) and number of nitroglycerin tablets consumed (3.4 +/- 4.9 to 1.2 +/- 2.5 tablets per week, p less than 0.05), and increased exercise duration (6.4 +/- 2.1 to 7.5 to 1.8 minutes, p less than 0.001) (all data are mean +/- standard deviation). These changes were significantly better than those seen with placebo. These beneficial effects of verapamil were related to significant reduction in the heart rate-systolic blood pressure product during submaximal exercise. Adverse effects from verapamil were few and consisted primarily of constipation in 6 patients. A total of 193 patients had been entered in 6 independent clinical trials, which have compared verapamil with placebo for the treatment of stable exertional angina pectoris, using a similar study design. The combined evidence from all these studies indicates that verapamil is a highly effective and safe drug for the treatment of stable effort-related angina pectoris.