PK Analysis in Toxicokinetic Studies

> What is the most appropriate way to naively pool plasma > concentrations for noncompartmental pharmacokinetic analysis > of data obtained in routine toxicokinetic studies in > rodents? There is no *appropriate way* to naively pool etc.! But less naive methods may be useful. > Is it appropriate to substitute missing BQL values with > zero, obtain the mean, then determine the pharmacokinetic > parameters? NO. (some questions are very easy to answer) Reason - Not so quick to write. BQL means less than some non-zero value. If you think your errors inmeasurement may be proportional to conc then putting a zero in is a long way from non-zero. > Is there a superior method for summarizing the > data? Should NONMEM be used? I look forward to your > comments. NONMEM could be used. If I understand your design each rat may have more than one conc measured. Thats all you need to get started on a non-naive analysis. Nick Holford