Ipazilide is an antiarrhythmic agent that prolongs ventricular refractoriness and possesses antiectopic activity. In clinical trials ipazilide administrations leads to dose- and time-dependent in decrease cardiac index and arterial pressure. Left ventricular filling pressure, right atrial pressure, and heart rate were not altered by ipazilide. Plasma concentrations of ipazilide peaked 90 minutes after administration of 100 or 200 of the drug, but peak concentrations were noted 3 hours after administration of 400 mg. The hemodynamic response correlated with the plasma concentration of ipazilide determined contemporaneously.