Comparative efficacy of bepridil versus placebo in angina pectoris: treatment and withdrawal studies.

The efficacy and safety of once-daily doses of 200, 300, and 400 mg of bepridil hydrochloride were compared with placebo in a 14-week multi-center, double-blind parallel study. All doses of bepridil significantly reduced weekly anginal attacks and nitroglycerin consumption from baseline levels. Bepridil also significantly improved total exercise time, time to angina, time to 1 mm ST-segment depression, and total work. Reduction in heart rate (maximum mean decreases of 7-8 beats/min) and prolongation of QT and corrected QT (QTc) intervals were associated with bepridil therapy. Bepridil was well tolerated; most adverse reactions reported were mild and tolerable even at the 400-mg dose. This study provides strong support for the use of bepridil in patients with chronic stable angina pectoris that is not optimally controlled by other available antianginal therapies. A double-blind withdrawal study is also reported, in which patients stabilized on bepridil were randomized to either continue on bepridil therapy or receive placebo. Patients who were withdrawn from bepridil therapy showed significant increases in the number of weekly anginal attacks and nitroglycerin consumption compared with levels seen during long-term treatment. Patients withdrawn from bepridil therapy showed significant deterioration in exercise tolerance compared with baseline and with those maintained on bepridil.