Enhancement of the efficacy of isosorbide dinitrate by captopril in stable angina pectoris.

This study was designed to assess whether the angiotensin-converting enzyme inhibitor captopril could potentiate the efficacy of a single dose of oral isosorbide dinitrate (ISDN) in patients with coronary artery disease. Fourteen men (mean age 53 years) with stable angina pectoris were studied. In each patient the efficacy of placebo, captopril (50 to 100 mg), ISDN (10 mg), and a combination of captopril (50 to 100 mg) and ISDN (10 mg) was assessed by repeated exercise treadmill tests performed before and 1, 2, 3 and 6 hours after administration of a single dose. A single-blind, randomized technique was applied. According to the mean data in the whole group of 14 patients, captopril alone produced no improvement in exercise duration to the onset of angina and to angina of moderate severity compared with placebo. The magnitude of ST-segment depression did not significantly change after captopril administration. ISDN alone significantly increased exercise duration to onset of angina and to angina of moderate severity (antianginal effect) and decreased the magnitude of ST-segment depression (antiischemic effect) 1 to 3 hours after administration. Combined administration of ISDN and captopril resulted in more expressed antianginal and antiischemic effects; at 2, 3 and 6 hours these effects with ISDN plus captopril were significantly more pronounced than those with ISDN alone. According to individual data, the most marked potentiation of ISDN efficacy was observed in patients who had poor response to ISDN alone. In all 6 patients in whom ISDN alone was ineffective, after the addition of captopril the desired antianginal effect was obtained.(ABSTRACT TRUNCATED AT 250 WORDS)