Bepridil hydrochloride for treatment of benign or potentially lethal ventricular arrhythmias.

To define the efficacy and safety of a new once-a-day calcium antagonist, bepridil, 21 patients with frequent ventricular premature complexes (VPCs) underwent a 14-day inpatient monitored trial. After Holter monitoring during placebo administration, patients underwent 2 days of a loading dose of bepridil followed by 12 days of bepridil, 400 mg/day. Holter monitoring during therapy showed that 10 patients (48%) had more than a 70% reduction in VPC frequency and 8 of 16 patients (50%) at least a 95% reduction in frequency of nonsustained ventricular tachycardia. Gastrointestinal and central nervous system side effects considered to be mild occurred in 13 patients (62%). One patient had an asymptomatic increase in VPC frequency and another had sustained ventricular tachycardia associated with a loading dose of 900 mg of bepridil. Thus, bepridil has moderate antiarrhythmic efficacy in patients with ventricular arrhythmias, but further definition of its potential for causing proarrhythmia must be determined.