Comparison of nitroglycerin-TTS and long-acting nitroglycerin tablets in the treatment of angina pectoris: a double-blind controlled study

Ointments and transdermal nitroglycerin patches for stable angina pectoris

Nitroglycerin (NTG) ointment is used for the prophylaxis against angina pectoris, but there are no data to support its effectiveness during long-term therapy. Continuous, once-daily application of isosorbide dinitrate cream produces tolerance with complete loss of efficacy within 1 week. Nitroglycerin patches are very popular and continuous once-daily application is still claimed by some investigators to provide 24 hour antiischemic and antianginal efficacy. This claim is based on data from postmarketing studies in a very large number of patients and placebo-controlled studies in smaller groups of patients from Italy, Yugoslavia, Greece, and Germany. In contrast, studies from the United States, Canada, England, and some centers in Germany have failed to show superiority of patches over placebo during continuous therapy. This controversy was addressed by the NTG cooperative study group, in which a total of 562 patients who were responders to sublingual nitroglycerin were studied. Patients received either placebo or NTG patches delivering low (15-30 mg/24 hr), moderate (45-60 mg/24 hr), or large (75 and 105 mg/24 hr) amounts of NTG. Four hours after the initial application, NTG patches increased exercise duration compared to placebo, but this beneficial effect had disappeared by 24 hours. Furthermore, after 8 weeks of continuous therapy, none of the NTG patches were superior to placebo, whether patients were or were not taking concomitant beta-blockers. Therefore, current opinion is that continuous therapy with NTG patches produces pharmacologic tolerance and is ineffective.(ABSTRACT TRUNCATED AT 250 WORDS)

The utility of Nitroderm TTS in angina pectoris: long-term treatment after switching from long-acting oral isosorbide dinitrate

Long-acting oral isosorbide dinitrate (ISDN) was replaced by Nitroderm TTS, and the utility of this drug in long-term treatment was assessed in 69 patients with angina pectoris. The frequency of attacks (p < 0.001) and the consumption of sublingual nitrate tablets (p < 0.01) were found to be significantly lower at 2 weeks to 6 months than in the observation period in patients who experienced attacks or received sublingual tablets during the observation period. On the other hand, no significant time-lapse changes from the observation period were noted in patients who experienced no attacks or received no sublingual tablets during the observation period. The symptoms of adverse effects were mild. The improvement rates (improved) of subjective symptoms and electrocardiogram (ECG) in Group A were about 50% after 6 months. On the other hand, the improvement rates (not aggravated) of subjective symptoms and ECG in Group B were more than 90%. Nitroderm TTS is considered a useful plaster preparation which can be used for sufficiently extended periods of time because its efficacy was as high as, or higher than, that of oral ISDN when this drug was administered over a long period of time after a switch from long-acting oral ISDN in angina pectoris patients.