Re: PD modeling: What is the most efficient approach to transfer data?

From: Nick Holford n.holford@auckland.ac.nz Subject: Re: [NMusers] PD modeling: What is the most efficient approach to transfer data? Date: Tue, 20 Dec 2005 17:03:47 +1300 Pavel, Where did you get this idea from? " Usually, it is not recommended to combine PK and PD models." If you read Zhang et al. I think you will find the opposite conclusion. i.e. best estimates are obtained by simultaneous analyis of PK and PD observations. Zhang L, Beal SL, Sheiner LB. Simultaneous vs. sequential analysis for population PK/PD data I: best-case performance. J Pharmacokinet Pharmacodyn. 2003 Dec;30(6):387-404. Because of time contraints you may wish to do sequential PK then PD analyses. Zhang et al describe 3 flavours -- PPP, IPP and PPPD. Overall they recommend the PPPD approach. This is quite easy to set up once you have combined the PK and PD observations into a single dataset. You just write the full model as if for a simultaneous analysis but FIX all the PK parameters. The data set includes the PK observations (the 'D' in PPPD) and the model uses the fixed population PK parameters (the 'PPP' in PPPD). Nick -- Nick Holford, Dept Pharmacology & Clinical Pharmacology University of Auckland, 85 Park Rd, Private Bag 92019, Auckland, New Zealand email:n.holford@auckland.ac.nz tel:+64(9)373-7599x86730 fax:373-7556 http://www.health.auckland.ac.nz/pharmacology/staff/nholford/