Validation of a variable direction hysteresis minimization pharmacodynamic approach: cardiovascular effects of alfentanil.

An important goal in therapeutics is the quantitative prediction of drug effects. Although several comprehensive pharmacodynamic models have been proposed, relatively few of these have attempted to assess objectively the application of the models to predict pharmacologic responses. A variable-direction hysteresis minimization approach was proposed recently that allowed the pharmacodynamics of drugs to be modeled using information about drug input. The application and validation of this approach are demonstrated using the pharmacodynamic effect of alfentanil, a short-acting narcotic analgesic agent, in New Zealand White rabbits. A parameter is proposed to assess the ability of the pharmacodynamic model to predict responses.