Propranolol Combined with Isosorbide Dinitrate versus Placebo in Angina Pectoris

Sublingual isosorbide dinitrate, 5 mg, combined with oral propranolol, 40 mg, was given four times daily for six weeks to 23 patients with angina pectoris. The effects were compared with those of appropriate placebos. Three patients (13 per cent) were unable to tolerate the drugs, seven (30 per cent) had fewer anginal attacks on the drugs, 10 (44 per cent) had fewer anginal episodes on the placebos, and three (13 per cent) had a similar number of anginal attacks on both drugs and on placebos. Five of 20 patients (25 per cent) had improved exercise performance on the drugs, and 15 (75 per cent) on the placebos. There was a significantly improved exercise performance in two patients (10 per cent) on the drugs and in eight (40 per cent) on the placebos. Propranolol and isosorbide dinitrate may harm as well as benefit patients with angina pectoris.