Pharmacological Actions and Their Computer Simulations

Computer simulations were made in several aspects of pharmacological actions in terms of a receptor-occupancy. 1) Functional and competitive interactions of two drugs in combination which were at equilibrium states. 2) Relative change of fractional receptor-occupancy of two agonistic drugs after a sudden change in their affinities. 3) Relative change of fractional receptor-occupancy of agonists and slowly acting and fast acting antagonists which resulted in the ”paradoxical potentiation”. 4) Frequency dependent change in receptor-occupancy of a drug due to a state‐dependent change in affinity. Various drugs may differ with respect to their relative potency depending on the situations at which these drugs are applied. It is emphasized that the construction of an appropriate model is essential which can not only reproduce the experimental findings in terms of a few simple and meaningful parameters but also serve as a successful working hypothesis for the future work.