&NA;The propafenone analogue diprafenone is a sodium channel antagonist with &bgr;-blocking properties. It has local anaesthetic and combined class Ic and II antiarrhythmic properties, and is being developed by Helopharm (Germany) for use in supraventricular tachyarrhythmias. It has been licensed to Boehringer Ingelheim for Germany, where it is undergoing phase III clinical trials. Licenses to Schering AG and Yamanouchi have been discontinued.