Differences in the antiischaemic effects of molsidomine and isosorbide dinitrate (ISDN) during acute and short-term administration in stable angina pectoris

The acute and short-term effects of treatment with 10 consecutive doses of isosorbide dinitrate 40 mg t.i.d. and molsidomine 8 mg t.i.d. in slow release formulations were investigated in 10 patients with angiographically documented coronary artery disease and stable angina pectoris according to a randomized, double-blind, double-dummy, cross-over study design using conventional symptom-limited exercise testing. Acute exercise testing 3 h following the first dose of ISDN and molsidomine showed a significant reduction of maximal ST segment depression and of the area above the ST segments. Time to occurrence of 0.1 mV ST segment depression, exercise duration, time to onset of angina and exercise tolerance increased significantly. On the fourth treatment day with ISDN and molsidomine an attenuation of these antiischaemic effects was seen. The mean effects on ST segment depression, area above ST segments, time to occurrence of 0.1 mV ST segment depression, exercise duration, time to onset of angina and exercise tolerance were reduced by 40%, 44%, 47%, 58%, 54% and 65%, respectively, in patients administered ISDN and by 33%, 48%, 58%, 59%, 45% and 60% in those given molsidomine. Thus, following sustained short-term therapy the antiischaemic effects of both drugs seem to be attenuated. In this report no marked differences were found between ISDN and molsidomine.