Therapy of Angina Pectoris with Propranolol and Long-Acting Nitrates

A double-blind study of the effects of isosorbide dinitrate, 10 mg given orally four times a day, propranolol, 40 mg four times a day, and the combination of these two drugs was performed on 21 patients with angina pectoris. Each patient received placebo, isosorbide, propranolol, and the combination of the two drugs for 1 month each in a random sequence over 4 months. The number of anginal pains and nitroglycerin tablets used were recorded, and a multistage treadmill ECG exercise test was performed after each treatment period. Frequency of anginal pains was reduced significantly with propranolol (7.0±2.5 pains/week) and the combination of propranolol and isosorbide dinitrate (9.9±2.9) as compared with placebo (21.0±6.4). Similarly, the number of nitroglycerin tablets was reduced with propranolol-containing regimens. Isosorbide was not significantly better than the placebo. Symptomatic improvement with propranolol could be related to a reduction in heart rate, and the product of heart rate and systolic blood pressure during exercise ( P