Randomized double-blind comparison of isosorbide dinitrate and nifedipine in variant angina pectoris.

The antianginal and anti-ischemic effect of isosorbide dinitrate (ISDN), 120 mg once daily, and nifedipine, 20 mg twice daily, both in slow-release formulations, were compared in 17 patients with variant angina pectoris in a randomized, double-blind trial. The design included a placebo run-in period and two 6-week crossover periods of active treatment. Mean frequency of angina decreased significantly from 43 attacks per week during the placebo period to 4 per week with ISDN and 8 with nifedipine (p less than 0.001). Sublingual nitroglycerin consumption decreased significantly from 37 tablets per week with placebo to 3 tablets per week with ISDN and 7 with nifedipine (p less than 0.001). Both drugs reduced the silent and symptomatic ST-segment deviations on ambulatory electrocardiographic recording and increased maximal exercise tolerance. Episodes of coronary spasm could be provoked, by hyperventilation, in all patients during the placebo phase but in no patient during therapy with either active drug. Thus, both ISDN and nifedipine, in their slow-release formulations, are effective in the treatment of variant angina pectoris.

[Comparison of isosorbide dinitrate and nifedipine in the treatment of variant angina pectoris. Randomized study]. / Srovnání isosorbid dinitrátu a nifedipinu v lécbe variantní anginy pectoris. Randomizovaná studie.

The effects of isosorbide dinitrate single dose 120 mg daily and nifedipine 20 mg twice daily were studied in 17 patients with variant angina pectoris due to coronary artery spasm. After a placebo phase the patients were randomized to treatment with either isosorbide dinitrate or nifedipine. After six weeks the patients were crossovered for another six weeks period of treatment. There was significant decrease of number of angina attacks during both treatment regimens. Using 24 hours Holter monitoring we also proved significant decrease of number of ST segment elevation or depression, either symptomatic or asymptomatic. There was increase of performed work during exercise tests after both treatment periods. The efficacy of Isoket 120 mg and Adalat Retard 2 x 20 mg daily in the treatment of patients with active variant angina pectoris was comparable in our study. 3 patients suffered untolerable headache during isosorbide dinitrate phase and had to terminate treatment after first day only.