[Comparative evaluation of antianginal efficacy of isosorbide dinitrate in various doses in patients with stable angina].

In a randomized, double-blind, placebo (P) controlled with cross-over design study 38 male patients with stable angina and angiographically proven coronary artery disease, received isosorbide dinitrate (ISDN) in various single doses: 10 mg, 20 mg, 20 mg slow-release (-SR), 40 mg-SR, 80 mg-SR and 120 mg-SR. Evaluation of antianginal efficacy and the effect of ISDN on the simple hemodynamic parameters was performed by analysis of walking times on the treadmill: total, to angina and to ischemia (WTI) as well as: heart rate and systolic blood pressure at rest and during exercise. Exercise stress tests on the treadmill were performed: preceding drug administration, 2 hours and 6 h after. 6 h after taking the drug all doses of ISDN improved significantly all three analysed walking times on the treadmill, for example WTI in comparison to P (p < 0.001): 10 mg by 34.6%, 20 mg by 49.6%, 20 mg-SR by 42.9%, 40 mg-SR by 52.5%, 80 mg-SR by 66.0%, and 120 mg-SR by 58.4%. ISDN 20 mg was more active antianginally than 10 mg, but was connected with more severe orthostatic hypotension and headaches. ISDN 20 mg-SR was weaker in the improvement of coronary reserve than ISDN 20 mg, but it gave less adverse effects. The elevation of ISDN-SR dose was effective in the improvement of coronary reserve up to 80 mg-SR (without further benefits after 120 mg-SR). The antianginal efficacy of doses: 40 mg-SR, 80 mg-SR and 120 mg-SR was not significantly different.