Mexiletine vs. lignocaine in the management of ventricular arrhythmias after open-heart surgery.

We made an open comparison of lignocaine and mexiletine in the treatment of ventricular arrhythmias occurring after open-heart surgery. Thirty patients whose arrhythmia did not respond to correction of metabolic disturbances were randomly allocated to receive treatment either with lignocaine or with mexiletine in fixed dosage schedules (15 in each group). Failure to control the rhythm or recurrent abnormality led to administration of a further dose and, if this was unsuccessful, to crossover to the alternative agent. The two drugs were comparable in efficacy, but mexiletine was slightly more effective when administered after lignocaine than the converse.