[Effects of prolonged-action nitrates on platelet aggregation and prostaglandin formation]

Platelet aggregation and prostaglandin levels were examined in 50 patients with coronary heart disease concurrent with Functional Classes II-III angina who received nitroglycerin-retard (n = 20; Group 1), corovas (n = 20; Group 2), and placebo (n = 10; Group 3). Long-acting nitrates were found to exert a positive action on thrombocytic hemostasis as decreased platelet aggregation and reverse aggregation in 25% of the corovas-treated patients. Placebo failed to have the same action. Nitroglycerin-retard caused an increase in prostacyclin concentrations. Nitroglycerin-retard and corovas produced a clear-cut antianginal effect. They promoted the reduction in the number of anginal episodes and of nitroglycerin tablets used. No antianginal effect was absent when placebo was used.