The convolutions of segmentally continuous zero- and first-order input functions with the general form of pharmacokinetic multicompartmental disposition functions can be used to analyze and simulate the time course of drug invasion into the central compartment of mammillary models and certain physiologically relevant recirculating systems. The generalized model equations may be used to assess the reliability and intercorrelations of parameter estimates directly, since partial derivatives with respect to all model constants can be computed explicitly. In combination with curve-fitting algorithms, input functions identical to those of the point-area deconvolution can be obtained, although at the expense of significantly longer computing times. On the other hand, the range of potential applications goes far beyond the reconstruction of the time course of drug absorption.