Antiarrhythmic therapy with flecainide in combination and comparison with propranolol.

In a prospective study of 10 patients with chronic ventricular arrhythmias, flecainide 50mg tid and propranolol 20mg tid were administered, alone and in combination, in a crossover design. Before and after each treatment phase, routine ECG and 24-hour ECG were recorded, morning plasma concentrations of the drugs were measured, and side effects recorded. Treatment with flecainide alone resulted in a 38% mean reduction (p less than 0.05) of ventricular premature complexes, a 75% (p less than 0.01) mean reduction of couplets, and elimination of ventricular tachycardia. At the dosage administered, propranolol alone had no antiarrhythmic effect. The combination of flecainide and propranolol showed no additional therapeutic benefit although there was a small, but not significant, increase in ventricular premature complexes and couplets. Use of flecainide resulted in a 12% widening of the QRS complex, with no significant change in PQ time, QTc and heart rate. Combined therapy with propranolol and flecainide resulted in a 12% decrease of average heart rate. The same effect was achieved when propranolol was given alone. The average plasma concentration of flecainide increased by 25% during combined therapy with propranolol. There were few side effects related to flecainide at the dosage administered and no additional side effects were recorded during the combined treatment.