A method of obtaining starting values of k(in) and k(out) for the indirect response models.

A method based on the multivariate technique known as principal component analysis is proposed to obtain starting values for the rate constants of indirect response models. The method is not iterative and only requires standard deviation calculations for two quantities, which are simple functions of the measured pharmacodynamic response. An algorithm is provided which can be implemented in a spreadsheet. The methodology is justified theoretically herein, nevertheless, two examples are provided to illustrate the method and demonstrate its viability.