Atrio-ventricular block after administration of lignocaine in patients treated with prenylamine.

Four patients are described who exhibited prolonged Q-T intervals, multiple ventricular premature beats and ventricular tachycardia of the 'torsade de pointes' configuration whilst on treatment with prenylamine. In two of these patients, advanced atrio-ventricular block was established immediately following intravenous administration of lignocaine. The arrhythmia and the atrio-ventricular blocks were successfully controlled by ventricular pacing. The hazard of the simultaneous administration of these two drugs is stressed.