Comparison of bepridil with nadolol for angina pectoris

Bepridil hydrochloride is a unique calcium channel-blocking drug with anti-ischemic and type 1 antiarrhythmic properties. With a half-life of more than 40 hours, once-daily therapy is possible. Twenty-four patients (22 men, 2 women), mean age 58 years (range 43 to 72), with stable exertional angina were assigned to therapy with bepridil and nadolol in a randomized, double-blind, crossover trial. Antianginal efficacy was assessed by a diary of angina frequency and nitroglycerin consumption as well as by treadmill exercise testing. The effect of therapy on ventricular function was assessed by symptom-limited equilibrium gated exercise radionuclide angiography. During therapy with both nadolol and bepridil, the number of episodes of angina per week was significantly reduced and nitroglycerin consumption decreased compared with baseline evaluation. Exercise duration was prolonged by both therapies (baseline 281 +/- 122 seconds, nadolol 377 +/- 96 seconds, bepridil 400 +/- 109 seconds; p less than 0.005 for nadolol and bepridil vs baseline). Time to the onset of angina was similarly prolonged, 50% by nadolol and 65% by bepridil (p less than 0.005). Bepridil had no effect on PR and QRS durations, although QTc was significantly prolonged (baseline 0.43 +/- 0.03, nadolol 0.42 +/- 0.03, bepridil 0.45 +/- 0.04; p less than 0.005 for bepridil vs baseline and nadolol). By radionuclide angiography, neither nadolol nor bepridil had an adverse effect on left ventricular function at rest or during exercise. Bepridil therefore provides effective therapy for angina without adverse effects on left ventricular function, comparable to the effects of beta blockade with nadolol.