Calcium antagonists diltiazem and nifedipine: Comparative efficacy in short-term (single-dose) and long-term regimens in patients with stable angina of effort

Aim. To compare efficacy of diltiazem and nifedipine in single dose and long-term treatment Materials and methods. A randomised double-blind cross-over study enrolled 17 patients suffering from coronary heart disease (CHD) with stable angina of effort (SAE). For 1 month, each patient received diltiazem and nifedipine (60-90 mg 4 times a day and 20-30 mg 4 times a day, respectively). The effect was assessed by the pharmacodynamic test after the initial dose and in the end of each treatment course. Results. In 14 eligible patients both drugs reduced the number of SAE attacks and nitroglycerin tablets, diltiazem efficiency being somewhat higher. Single doses of diltiazem and nifedipine produced the same action. In long-term treatment nifedipine effect became shorter, diltiazem effect did not change. Before the morning dose of nifedipine (11.5 hours after the previous dose) exercise tolerance of this drug worsened. This may be due to withdrawal syndrome. As to diltiazem, its exercise tolerance improved. Conclusion. In long-term treatment of CHD with SAE: diltiasem is more effective and safe than nifedipine.