[Clinical usefulness of high-dose oral nitroglycerin in patients with stable angina pectoris].

The aim of this study was to evaluate clinical efficacy and adverse effects of nitroglycerin 15 mg in slow-release form (N-15) after single ingestion. In randomized, double-blind and placebo (P) controlled with cross-over design study 15 male patients with stable angina received N-15 or P. Antianginal efficacy of the drug was evaluated by analysing the parameters of tolerance of effort and coronary reserve taken from serial exercise stress tests on treadmill performed preceding single oral ingestion, 2 hours and 6 hours after. Simple hemodynamic parameters were also evaluated in the rest and during exercise. N-15 significantly improved in comparison to P: total walking time both after 2 hours by 34.3% (p < 0.01) and 6 hours by 23.1% (p < 0.01); walking time to angina after 2 hours by 34.8% (p < 0.01) and 6 hours by 21.7% (p < 0.05), and walking time to ischemia after 2 hours by 66.1% (p < 0.01) and 6 hours by 39.0% (p < 0.05). N-15 significantly increased the rest heart rate in standing position 2 hours after ingestion by 12.3% (p < 0.01) and decreased rest systolic blood pressure in both positions 2 hours after ingestion: in supine by 12.9% (p < 0.01) and standing by 16.3% (p < 0.01) and after 6 hours: in supine by 9.1% (p < 0.05) and standing by 10.0% (p < 0.05). No postural hypotension in any patient occurred. Diastolic blood pressure was significantly decreased only in standing position 2 hours after N-15 ingestion by 12.3% (p < 0.01) and after 6 hours by 9.1% (p < 0.05). During maximal exercise significant reduction of systolic blood pressure occurred 2 hours after ingestion and significant reduction of diastolic blood pressure occurred both 2 hours and 6 hours after ingestion. Adverse effects after single ingestion of N-15 were the few: the headaches were presented only in 4 patients (27%), and in 53% patients any adverse effect occurred. Nitroglycerin 15 mg in slow-release form is an active coronary drug, effective not less than 6 hours after ingestion, and its adverse effects are the few.