Acute and chronic efficacy of low-dose nitroglycerin patches in stable angina pectoris.

In a single-blind placebo controlled study, acute and chronic efficacy of low-dose nitroglycerin patches (NTG 5 mg/day) was studied in 24 patients with stable angina pectoris. NTG patch effects were evaluated by means of the multistage treadmill exercise test. During the acute study one exercise test was carried out after the wash-out period, after placebo patch (5 hours after application) and NTG patch (5, 16, 20 and 24 hours after application), so that a 3 day wash-out period had preceded each exercise test. Afterwards, chronic NTG patch therapy was continued for three months. At the end of this period exercise tests were carried out, in three day intervals of therapy, 5, 16, 20 and 24 hours after therapy. Then, a 7 day placebo patch period was continued with one exercise test at the end, 5 hours after application. Statistical analysis was carried out by multivariate analysis of difference. Systolic and diastolic blood pressure at rest fell significantly only in the acute 5 hour measurement, with no change in the other periods. The NTG patch augmented significantly mainly all heart rate values during exercise test, with no change in resting values. Placebo, acute and chronic exercise tests did not show any significant difference. They showed a slight but significant placebo influence on the exercise test compared to the wash-out period, improving maximum walking time and time to the onset of angina pectoris but with worsening of maximum ST-depression.(ABSTRACT TRUNCATED AT 250 WORDS)