RESUMO
In 10 subjects with constant threshold effort angina ascertained by two bicycle exercise tests, the efficacy of a new transdermal preparation of nitroglycerin (104 mg) applied once daily was evaluated and compared to that of oral long-acting isosorbide dinitrate (20 mg every 8 hours). The two drugs were administered according to a complete crossover plan. The effectiveness of each drug was evaluated by testing the patients before treatment, on the third and on the twenty-first hour of treatment. In each case the exercise was continued until electrocardiographic signs of ischemia appeared. The total work during treatment with transdermal nitroglycerin was significantly higher (average increase greater than 44%) than without the drug (1311 +/- 545 Kgm before treatment, 2145 +/- 968 Kgm at the third hour, 1899 +/- 657 Kgm at the twenty-first hour of treatment). Similar results were obtained during treatment with isosorbide dinitrate (1332 +/- 581 Kgm before treatment, 1837 +/- 526 at the third hour, 1869 +/- 570 at the twenty-first hour of treatment; average work increase greater than 37%). In conclusion, with this new transdermal preparation of nitroglycerin an increased work-load can be achieved before ischemia appears. Its beneficial action remains constant for 21 hours.
