Statistical model and inference for pharmacokinetic data

Abstract

In this paper, we consider a statistical model for the drug concentration–time profiles that are obtained in a pharmacokinetic (PK) study when the drug is orally administered. In the proposed statistical PK model, the subject-specific concentration–time curve is described by the one-compartment PK model with first-order absorption and elimination. Moreover, a multivariate generalized gamma distribution is developed for the joint distribution of the drug concentrations that are repeatedly measured from the same subject. We then construct confidence intervals for the subject–exposure parameters which provide a further insight into the individual exposure of the drug under study. The proposed statistical PK model and the associated inference are then applied to illustrate a real data set. A simulation study is also implemented to investigate the performances of the coverage probability and expected length of the proposed confidence intervals. Finally, we give conclusions and discussions on the application of the proposed procedures.

Keywords:

• drug concentration–time profile
• multivariate generalized gamma distribution
• one-compartment pharmacokinetic model

Acknowledgements

We appreciate the constructive comments and suggestions by the associate editor and referee which greatly improve the presentation of the materials in this paper. Contract/grant sponsor: National Science Council of Taiwan, contract/grant number: NSC97-2118-M-008-003-MY2.