Effects of bepridil on exercise tolerance in chronic stable angina: a double-blind, randomized, placebo-controlled,...

Bepridil, a calcium antagonist with a half-life of approximately 42 hours, was compared with placebo in a double-blind, randomized, crossover trial. Thirteen men (average age 62 years) with exercise-related angina pectoris and a positive exercise test (modified Bruce protocol) were studied. In the group as a whole, bepridil (400 mg once a day) caused an increased total exercise time (2.6 +/- 1.8 minutes, mean +/- standard deviation), time to onset of angina (3.3 +/- 1.6 minutes), time to 1 mm of ST-segment depression (2.2 +/- 2.3 minutes), time to 2 mm of ST-segment depression (2.4 +/- 1.4 minutes) and total work load achieved (1.8 +/- 1.4 kpm) compared with the preceding placebo phase (all p less than 0.05). Frequency of angina and nitroglycerin consumption were low and did not change significantly during bepridil therapy. Comparison of the 3 placebo periods (run-in, double-blind and washout) did not reveal a change in any measurement except time to onset of angina, suggesting no training effect or change in patient status. Adverse effects were common in patients taking both placebo and bepridil, but only 2 patients had adverse effects (dizziness) with bepridil that necessitated discontinuation of therapy. Similarity of the double product (systolic blood pressure X heart rate) at the end of exercise suggests a decrease in myocardial oxygen demand as the primary mode of action. This study suggests that bepridil is a promising agent for the treatment of exercise-induced myocardial ischemia.