Population pharmacokinetic profiling during early Phase I/Phase II testing has provided pharmacokinetic information early in the clinical development of an investigational cardiotonic compound. While development of a population pharmacokinetic profile can be a continuous evolutionary process, initial analyses suggest imazodan clearance to be influenced by hemodynamic and hepatic status in severe congestive heart failure patients. Volume of distribution appears to be proportional to body size, but the magnitude of this relationship is probably not clinically significant. Following oral administration, imazodan is generally rapidly absorbed; however, interindividual variability in this process is large. Imazodan bioavailability appears to be good considering the severity of congestive heart failure and altered hemodynamics in this patient population.