Physiological spaces and multicompartmental pharmacokinetic models

The idea of body compartments has its origins in physiology and antedates their use in both physiologically-based predictive pharmacokinetic models and in the simpler compartmental models used to analyze pharmacokinetic data. Whereas physiologically-based pharmacokinetics has evolved to use increasingly sophisticated organ-based models, most compartmental models for data analysis are used without regard for their underlying physiological basis. However, detailed analysis of inulin and urea kinetics has offered some understanding of the physiological basis underlying some three-compartment pharmacokinetic models. In addition, these simple models have yielded new insight into physiological phenomena.