[Prolonged hemodynamic effects of a nitroglycerin microcapsule preparation administed orally (author's transl)]

The hemodynamic effects of a microcapsule nitroglycerin preparation (Lénitral) were studied in 30 patients. Ten patients received 2 capsules of Lénitral 2,5 mg equivalent to 5 mg nitroglycerin; ten patients received 1 capsule of Lénitral 7,5 mg equivalent to 7,5 mg nitroglycerin, and ten patients received a placebo. Central venous pressure (CVP), systemic arterial pressure (AP) and heart rate (HR) were monitored during 12 hours. In the two groups treated, there was a significant decrease in CVP, starting 30 minutes after administration, lasting until the 8th hour and followed by a gradual increase; HR remained unaltered. AP was only lowered in patients under Lénitral 7,5 mg. There were no changes in these parameters among patients under placebo. In addition, 10 patients were catheterized one hour after oral administration of either 2 capsules of Lénitral 2,5 mg or a placebo. In the patients treated there was a significant decrease in right and left ventricles filling pressure, without changes in HR, AP, cardiac index and peripheral systemic resistances. At the end of the study, administration of 0,6 mg sublingual nitroglycerin produced no further changes in these parameters, in contrast with patients under placebo. The study indicates that Lénitral exerts prolonged hemodynamic effects and that low doses act primarily on preload and higher doses on both preload and afterload. This makes Lénitral a valuable drug for long-term treatment of chronic coronary disease and congestive heart failure.