Pattern recognition and multivariate time-dependent structure-activity relationships were applied to a series of N-4-substituted 1-(2-arylethyl)-4-piperidinyl-N-phenylpropanamides. A correct classification of drugs to similar clusters requires identical results obtained from biological and chemical pattern recognition. The time point of the bioassay determines the significance of physicochemical features, and it was shown that substituent contributions vary within the time of bioassay.