Multiple comparison of several antiarrhythmic agents by acute oral drug testing in patients with chronic ventricular arrhythmias

This study addresses the question of the choice of treatmentfor the individual patient with chronic ventricular arrhythmias.Acute oral drug testing offers a pragmatic approach to the rapidselection of the drug with the best efficacy/side-effect ratioby allowing multiple comparisons within the same patient. Fortypatients with chronic ventricular arrhythmias received a singleoral dose of the following antiarrhythmic drugs: flecainide200 mg, propafenone 450 mg, disopyramide 300 mg, mexiletine400 mg, tocainide 800 mg, verapamil 160 mg, propranolol 120mg. Criteria for efficacy were suppression of complex ventriculararrhythmias and a > 90% reduction in premature ventricularbeats lasting for at least 2 h. An antiarrhythmic effect was achieved with each of the drugsin the following percentages of patients: flecainide 69·;4%,propafenone 67·5%, disopyramide 54·;8%, mexiletine45·2%, tocainide 31·;3%, verapamil 31·3%,propranolol 12·5%. In no case was worsening of arrhythmiaobserved. At the end of the acute testing phase, the drug thathad proved most effective in each patient was administered ata full dosage for 72 h. A concordant response between the twophases was observed in 80% of patients and was as high as 89%when the analysis was limited to flecainide and propafenone. This study shows the feasibility and practical advantages forpatient management of a multiple comparison of antiarrhythmicdrugs by acute oral drug testing. It also provides, in a non-invasivecost-effective manner, unique insights into the complex relationshipbetween drug characteristics, individual responses and clinicalefficacy.