[Orally administered nitroderivates: efficacy and duration of the effects of isosorbide dinitrate (author's transl)].

The effects of 20 mg of orally administered isosorbide dinitrate on 10 patients with stable angina pectoris were studied by means of exercise tests. First, the reproducibility of the angina threshold of each patient was controlled; then the effects after 60, 150 and 210 minutes after administration of the drug and of a placebo, given in a random sequence, were studied. No significant changes of the parameters examined were observed after the placebo. A significant increase of duration of exercise and total amount of work performed before appearance of angina were observed after the drug. These changes were maximal in tests made 60 minutes after administration of the drug, declining thereafter; nevertheless, statistically significant differences from placebo were also observed in tests performed after 150 and 210 minutes. The appearance of ischemic ST changes was retarded by the administration of the drug. Disappearance of pain after interruption of exercise was significantly quicker when compared with the observations made after placebo.