RE: between-patient variability in PK and PD

From: "Bhattaram, Atul" BhattaramA@cder.fda.gov Subject: RE: [NMusers] between-patient variability in PK and PD Date: Wed, May 4, 2005 11:26 am Hello Mathot Couple of comments: 1. It is better to use concentrations rather than AUC in the model to derive PK/PD relationships. 2. Even without the use of any model, just looking at the data do you think that there is a lot of variability in the effects? 3. If PK is not very variable, but PD is highly variable then I would suggest to look for sources to minimize this variability if possible. 4. Having reasonable information on drug concentrations in your registration trials will always help you in identifying and justifying any findings which you might not anticipated based on the limited experience from early dose-response studies. Venkatesh Atul Bhattaram Pharmacometrics US Food and Drug Administration