Evaluation of Nitroglycerin in Angina in Patients on Isosorbide Dinitrate

Seventeen male patients with angina pectoris due to coronary artery disease who had not received long-acting nitrites for at least 1 mo prior to this study were evaluated in a double-blind crossover study to investigate whether the presence of isosorbide dinitrate interfered with the effective response of exercise-induced angina to nitroglycerin administered sublingually. There was no significant difference in the duration of angina following nitroglycerin whether the patients were on no medication, sublingual placebo or sublingual isosorbide dinitrate. There was no significant difference in the blood pressure, heart rate, product of systolic blood pressure and heart rate, or electrocardiographic response after the complete relief of angina following sublingual nitroglycerin whether the patients were on no medication, sublingual placebo, or sublingual isosorbide dinitrate. These results indicate that long-acting nitrites do not cause any clinical impairment of the effective response of angina pectoris to sublingually administered nitroglycerin.