[Treatment of stable exercise angina with calcium blockers-a double-blind, placebo-controlled comparison of diltiazem and nifedipine].

In a placebo-controlled, randomized double-blind study, 43 out-patients with stable angina pectoris were treated for 2 months with a calcium-antagonist. 9 patients received a constant dose of 60 mg diltiazem t.i.d.; 12 patients underwent a dose increase to 90 mg t.i.d. after 4 weeks of treatment because of insufficient therapy response. In 5 patients 10 mg nifedipine t.i.d. was sufficient, 17 patients received 20 mg t.i.d. during the second part of the study. The patients were examined and subjected to symptom-limited ergometric tests at 2-week intervals. Under both medications, the frequency of anginal attacks decreased significantly; this was accompanied by a concomitant decrease of nitroglycerin consumption. During the tests, the time to occurrence of anginal complaints and thereby work capacity increased. ST-depression and ST-index were diminished. Heart rate, blood pressure and pressure-rate product did not change at rest or under exercise. There was no statistically significant difference between the two calcium-antagonists. Patients who showed satisfactory results under one of the two medications participated in an open, uncontrolled long-term trial and were treated with 60 mg or 90 mg diltiazem t.i.d. over a one-year period. There were no clinically remarkable events on changing from nifedipine to diltiazem. The monthly controls and the quarterly ergometric tests showed an unchanged efficacy of diltiazem. During the double-blind short-term treatment, the frequency of side effects was slightly lower under diltiazem than under nifedipine. Long-term treatment especially confirms the good tolerance of diltiazem.