Pincainide is a new beta-amino anilide with local anesthetic properties. It has been shown to be 3 times more potent than lidocaine as a local anaesthetic on desheathed frog sciatic nerve. It was found to be effective against arrhythmias induced in guinea-pigs by ouabain infusion or by administration of adrenaline and chloroform. Pincainide not only inhibited the influx of Ca 2+ and increased 45Ca efflux, thus reducing the contractile responses induced in rat aorta by noradrenaline and high K +, but it also inhibited other effects related to the noradrenaline-induced release of intracellular Ca 2+ stores. Further studies, however, must be performed in experimental models of arrhythmias before the effectiveness of pincainide as an antiarrhythmic drug can be established.