Drug administration currently takes the form of sophisticated vectors and techniques designed to reproduce as closely as possible the physiological regimens the medication tries to replace. We discuss a number of examples in which the normal condition is not stationnary, and thus therapeutic interventions must be determined in terms of pulsatile release, for example, or some form of oscillation.

We also present a model to describe the time course of plasma concentration of neuromuscular blocking agents used as anaesthetics during surgery. The model overcomes the limitations of the classical compartmental models commonly used in pharmacokinetics by incorporating spatial effects due to heterogeneity in the circulation.