(±)-SDZ-201 106 is a diphenylpiperazinylindole derivative that prolongs the open state of cardiac voltage-gated Na channels. It has been shown to increase net Na influx and the activity of reverse mode Na/Ca exchange, which leads to an increase in intracellular Ca, as well as to partially inhibit the Na pump in cardiac myocytes. (±)-SDZ-201 106 is also reported to act as an open-channel blocker of delayed-rectifier K channels in NG108-15 neuronal cells.