Statistical Aspects in the Pharmacokinetic Analysis of Clinical Phase 1 Trial —The Distribution and Summay Statistics of Pharmacokinetic Data

This paper reviews the statistical aspects in pharmacokinetic analysis of clinical Phase 1 trials. Based on the understanding that most pharmacokinetic parameters follow a lognormal distribution, it is considered to be appropriate to summarize them by the geometric mean, geometric CV or geometric SD. Then we conducted simulation studies of a pharmacokinetic model to investigate whether pharmacokinetic parameters follow a lognormal distribution. Using numerical examples obtained by the simulation, we described in detail how to display the summary statistics of pharmacokinetic parameters. We also indicated that geometric mean is also useful to summarize the plasma concentration, and that the concetration below the lower limit of quantification shoud be carefully handled.