PL
The purpose of the paper is to determine the structure of the functional explanations given in the process of designing pharmacological therapies in biological and medical sciences. The article shows that neither the classical models of functional explanation (presented by Hempel and Nagel) nor Cummins's functional analysis provide an adequate account. A brief discussion of these models becomes the point of departure for suggesting a functional-causal explanatory model (FP). The model is put to use in a reconstruction of the pharmacological cardioprotective therapy project.