Efficacy of diltiazem for control of symptoms of coronary arterial spasm.

To evaluate the efficacy of the calcium antagonist diltiazem for therapy of active coronary arterial spasm, 13 patients with clinical variant angina attributed to documented coronary arterial spasm completed a prospective randomized double-blind crossover trial of diltiazem (120 and 240 mg/day) versus placebo. Response was assessed with the diary technique measuring frequency of angina, consumption of nitroglycerin and percent of pain-free days. When 120 mg of diltiazem/day was compared with the paired placebo period there was a significant increase in percent of pain-free days (from 43 to 71 percent [p = 0.03]), but no significant decrease in frequency of angina (p = 0.06) or consumption of nitroglycerin (p = 0.32). When 240 mg of diltiazem/day was compared with the paired placebo period there was a significant increase in percent of pain-free days (from 50 to 79 percent [p = 0.03]) and a significant decrease in both frequency of angina (from 1.6 to 0.4 episodes/day [p = 0.03]) and consumption of nitroglycerin (from 1.3 to 0.4/day [p = 0.01]). Diltiazem was found to be a highly effective drug for control of symptoms of active coronary arterial spasm, without side effects and with excellent patient tolerance.