Acute and chronic efficacy of 10 mg of nitroglycerin patch in stable angina pectoris

In a single-blind placebo-controlled study, acute and chronic efficacy and duration of action over 24 hours with a 10-mg nitroglycerin (NTG) patch was studied in 24 patients with stable angina pectoris. NTG patch effects were evaluated by means of a multistage treadmill exercise test. During the acute study, exercise tests were performed after the washout period, after placebo patch (5 hours postdosing) and NTG patch (5, 16, 20 and 24 hours postdosing); a 3-day washout period preceded each test. After 3 months of therapy with the NTG patch, exercise tests were performed in 3-day intervals of continuous therapy 5, 16, 20 and 24 hours after patch application. Then, after 7 days of placebo patch therapy, 1 exercise test was performed 5 hours after application. Statistics were obtained by multivariate analysis of difference. Placebo acute and chronic tests did not show any significant difference when compared. Acute and chronic NTG patch tests, (5 to 24 hours) showed significant improvement of maximal exercise time, the time to onset of 1.0 mm ST-depression and to onset of angina as well as maximal ST depression and ST depression 3 and 6 minutes after exercise testing compared with placebo. These effects were significant over 24 hours after acute or continuous therapy, although all values started to decrease after 16 hours, with a decrease of 10% during the acute and of 15% during the chronic period, compared with values at 5 hours. The efficacy was maintained during 3 months of chronic therapy, even with slightly greater magnitude compared with acute administration, mainly during the time of the first angina and 1.0 mm of ST depression.(ABSTRACT TRUNCATED AT 250 WORDS)