Antiarrhythmic efficacy and tolerance of oral propafenone in patients with frequent ventricular arrhythmias: experience of a multicentre study.

In a multicentre study efficacy and safety of propafenone 450 mg day-1 and 750 mg day-1 was studied in 97 patients with frequent ventricular premature beats (VPB greater than 30 h-1). 70 patients suffered from organic heart disease, in 27 patients no organic heart disease was present during an initial work-up. After a 1-week washout period, all patients underwent 24 h Holter monitoring. Patients were then treated by propafenone 450 mg day-1 and controlled for 24 h Holter, ECG, blood pressure, blood chemistry and side-effects after 1 week of treatment. At this time, 35 patients were responders (reduction of VPB greater than 84%, of ventricular pairs greater than 90% and of ventricular tachycardia 100%). The mean reduction of VPB in all patients was 60%, of ventricular pairs 88% and of ventricular tachycardia 100%. When treatment was continued for 3 weeks 20/35 patients (56%) were still responders. The mean reduction of VPB was 83%. In 42 non-responders to 450 mg day-1 the dose was increased to 750 mg day-1. Of these patients, 17 (41%) became responders after 3 weeks of treatment; the mean reduction of VPB increased from 17% (first week, 450 mg day-1) to 63% (750 mg day-1). Ventricular pairs were reduced by 80%, ventricular tachycardia by 100%. Side-effects occurred in 11/97 patients and limited therapy in six patients. The most frequent complaints were dryness of the mouth, nausea, tiredness, headache and gastrointestinal upset. In conclusion, propafenone in a dose of 450-750 mg day-1 seems to be an effective and safe antiarrhythmic agent in the majority of patients.