Symposium on verapamil, therapy for angina pectoris. Part III: Studies in effort-related anginaCalcium channel blockade as primary therapy for stable angina pectoris: A double-blind placebo-controlled comparison of verapamil and propranolol

The effectiveness and safety of the beta-adrenergic blocking agent propranolol and the calcium channel antagonist verapamil were compared in 22 patients with chronic stable angina pectoris using a double-blind randomized placebo-controlled crossover protocol. The double-blind phase was preceded by a 2 week single-blind placebo period, followed by randomization to either either 4 weeks' therapy with verapamil, 360 mg/day, or propranolol, 240 nig/day, followed by crossover to the other drug. Both verapamil and propranolol increased exercise tolerance (5.5 ± 0.4 minutes with placebo, 7.8 ± 0.5 minutes with propranolol [p <0.001], and 9.1 ± 0.5 minutes with verapamil [p <0.001]), but the increase with verapamil was significantly greater (p <0.01). Both drugs prolonged the exercise duration to 1 mm S-T depression (3.3 ± 0.4 minutes with placebo, 5.7 ±0.5 minutes with propranolol [p <0.001] and 5.5 ±0.6 minutes with verapamil [p <0.001]); the degree of improvement was similar with both active drugs. Both drugs decreased the resting heart rate (76 ±3 beats/min with placebo, 56 ± 2 beats/min with propranolol [p <0.001], and 71 ± 3 beats/min with verapamil [p <0.01]), but the heart rate decreased more with propranolol than with verapamil (p <0.001). Neither drug produced significant adverse reactions. This study, along with 8 similar double-blind placebo-controlled randomized investigations which have compared verapamil with propranolol, indicate that verapamil is as effective and safe as propranolol in relieving symptoms and improving exercise tolerance in patients with chronic stable angina pectoris and may be considered a first-line therapeutic agent in patients with ischemic heart disease.