Diprafenone closely resembles propafenone in both structure and function. It is beta adrenoceptor antagonists and sodium channel antagonists. Diprafenone is highly protein bound in plasma. It has demonstrated efficacy against supraventricular and ventricular arrhythmias in clinical trials. Diprafenone produced first-degree atrioventricular block in 6/20 patients tested with coronary artery disease and sustained ventricular tachycardia. Intravenous application of diprafenone significantly increased atrioventricular nodal conduction time as well as the effective refractory periods of the right ventricle and the accessory pathway in both the antegrade and retrograde directions in 15 patients with the Wolff-Parkinson-White syndrome and symptomatic supraventricular tachycardia.