Grey dynamic model of predicting the long-term effects of drugs and its application to pirenzepine

In an attempt to approach the quantification of the dynamics of drug effects and the prediction of the long-term effects of drugs, a grey dynamic model was proposed and it was applied to predict the long-term effects of pirenzepine on pupils and peripheral leukocytes in dogs. The inconsiderable relative errors between the predicted and observed values suggest that the model-based equations for pupil diameter, neutrophils (%) and lymphocytes (%) which, obtained by fitting the data measured before and during initial 16 wk experiment, are acceptable for predicting the effects after 20- and 24-wk treatment with the drug.