PK/PD modeling - fixing population paramterers vs. fixing both pop. and individual parameters

1 messages 1 people Latest: Feb 01, 2012
Pavel, These papers explore the different options for modelling PK and PD data. Zhang L, Beal SL, Sheiner LB. Simultaneous vs. sequential analysis for population PK/PD data I: best-case performance. J Pharmacokinet Pharmacodyn. 2003A;30(6):387-404. Zhang L, Beal SL, Sheiner LB. Simultaneous vs. sequential analysis for population PK/PD data II: robustness of methods. J Pharmacokinet Pharmacodyn. 2003B;30(6):405-16. A variant on the IPP method is described here: Lacroix BD, Friberg LE, Karlsson MO. Evaluating the IPPSE method for PKPD analysis [www.page-meeting.org/?abstract=1843]. PAGE 19. 2010. Its usually best to fit the PK data then fix the parameters and explore the PKPD model without changing the PK part. Once you have a good fit you can then try a simultaneous fit. If the PK model parameters change a lot this may be a sign of mis-specification of the PK to PK link (Zhang 2003B). Nick On 2/02/2012 5:15 a.m., nonmem > > Hello NONMEM Team, > > We usually try to separate PK and PD models and the reasons are > obvious. There are different ways to separate the models. Are there > any good references which show advantages and disadvantages of fixing > population paramterers in the PD model ann allowing the model to > estimate individual PK parameters vs. fixing both population and > individual PK parameters? > > Thanks! > > Pavel > -- Nick Holford, Professor Clinical Pharmacology Dept Pharmacology& Clinical Pharmacology, Bldg 505 Room 202D University of Auckland,85 Park Rd,Private Bag 92019,Auckland,New Zealand tel:+64(9)923-6730 fax:+64(9)373-7090 mobile:+64(21)46 23 53 email: n.holford http://www.fmhs.auckland.ac.nz/sms/pharmacology/holford