Clinical Evaluation of the Antianginal Effects of Transdermal Therapeutic System-Nitroglycerin (TTS-NTG) by the Serial Multistage Treadmill Exercise Testi

A placebo-controlled study was performed in 13 patients with stable effort angina pectoris in order to evaluate the effect of TTS-NTG on exercise tolerance. Multistage treadmill exercise testing was performed according to the modified Bruce protocol before and 2, 7, and 24 hours after a single topical application of a placebo identical in appearance to the active TTS-NTG at 9: 30 to 10: 00 am. One or 2 days later, the exercise testing was repeated on active TTS-NTG at 25mg/10 cm2 or 50mg/20cm2.1) In the pre-treatment period, there were no significant differences in exercise duration, pressure-rate product (PRP), or ST deviation between TTS-NTG placebo/10cm2 and TTS-NTG 25mg/10cm2. There was no significant difference in exercise duration between placebo/20cm2 and TTS-NTG 50mg/20cm2, but at the exercise endpoint, TTS-NTG 50mg/20cm2 increased PRP and tended to increase ST deviations.2) Both TTS-NTG 25mg/10cm 2 and 50mg/20cm2 significantly prolonged or tended to prolong exercise duration at 2, 7, and 24 hours after topical application as compared with the control (data from the placebo study of corresponding duration).3) In comparison with the control, PRP at the endpoint significantly increased or tended to increase with TTS-NTG 50mg/20cm2, but showed no constant tendency with TTS-NTG 25mg/10cm2.4) Active TTS-NTG showed no significant changes in ST deviation at the endpoint as compared with the control.5) The mean plasma nitroglycerin concentration was maintained within the ranges of 0.29 to 0.34ng/ml and 0.30 to 0.41ng/ml during the interval of 2 to 24 hours after a single application of TTS-NTG 25mg/10cm2 and 50mg/20cm2, respec tively. In one patient in whom the exercise testing was also conducted with TTSNTG 50mg/20cm2, the plasma concentration reached a higher level and the exercise duration was much more prolonged as compared with TTS-NTG 25mg/10cm 2.In conclusion, it was demonstrated that TTS-NTG maintained a constant plasma concentration of nitroglycerin through 24 hours after a single application and improved the exercise tolerance in patients with stable effort angina pectoris. Thus, it is concluded that TTS-NTG is a useful long-acting antianginal agent.