[TTS-nitroglycerin and slow-release metoprolol: efficacy in patients with stable exercise-induced angina]

The antianginal efficacy of slow-release metoprolol (SRM) alone and associated to a transdermal therapeutic system containing nitroglycerin (TTS-TNG), was investigated in 10 patients with chronic, stable exertional angina and angiographic evidence of obstructive coronary artery disease, by means of a double blind, cross-over trial. Each patient performed a symptom-limited exercise test 4 and 24 hours after single blind placebo on day 1, and double blind SRM (200 mg) alone or SRM plus TTS-TNG, on days 3 and 5, in a randomized sequence. The protocol of Redwood was employed. Compared to the beta-blocker alone, the combined administration of SRM and TTS-TNG was associated to a significant increase in mean exercise duration 4 hours (528 +/- 180 vs 412 +/- 110 sec.; p less than 0.001) and 24 hours (432 +/- 115 vs 391 +/- 100 sec.; p less than 0.05) after drug administration. A significant increase in mean total work performance 4 hours (4626 +/- 1070 vs 3272 +/- 803 kgm; p less than 0.01) and 24 hours (3445 +/- 1045 vs 2941 +/- 773 kgm; p less than 0.01) after drug administration was observed as well. During placebo all the tests were stopped due to angina associated with ST depression greater than or equal to 1 mm. Conversely, the test was terminated due to fatigue by 8 patients at 4 hours and 5 patients at 24 hours after combined therapy, and respectively by 5 and 1 patient after SRM alone. No side effects were observed after the administration of SRM alone, whereas 5 patients complained of mild headache after SRM and TTS-TNG.(ABSTRACT TRUNCATED AT 250 WORDS)