Re: non-linear PK

From: "Perez Ruixo, Juan Jose [PRDBE]" JPEREZRU@PRDBE.jnj.com Subject: Re: [NMusers] non-linear PK Date: Thu, 6 Oct 2005 18:51:56 +0200 Dear Jing, The input from the second compartment to the first compartment is missing. Probably what you want to fit is a system of DE as follows DADT(1) = - K12*A(1) + K21*A(2) - A(1)*VM/(KM+C1) DADT(2) = K12*A(1) - K21*A(2) - K23*A(2) + K32*A(3) DADT(3) = + K23*A(2) - K32*A(3) However, I'm not sure you want to start with a catenary model, instead of a mamillary model. If you like to test a mamillary model, it should be as follows: DADT(1) = - K12*A(1) + K21*A(2) - K13*A(1) + K31*A(3) - A(1)*VM/(KM+C1) DADT(2) = K12*A(1) - K21*A(2) DADT(3) = + K13*A(1) - K31*A(3) Regards, Juan Jose Perez Ruixo, PhD. Principal Scientist. Advanced PK/PD Modelling & Simulation, Global Clinical Pharmacokinetic and Clinical Pharmacology, Johnson & Johnson Pharmaceutical Research & Development, a Division of Janssen Pharmaceutica, NV. Email: jperezru@prdbe.jnj.com