nlmeODE (version 0.2-1)

IndomethODE: Pharmacokinetic modelling of Indomethacin using differential equations

Description

The Indometh data frame has 66 rows and 3 columns of data on the pharmacokinetics of indomethacin.

source

Kwan, Breault, Umbenhauer, McMahon and Duggan (1976), ``Kinetics of Indomethacin absorption, elimination, and enterohepatic circulation in man'', Journal of Pharmacokinetics and Biopharmaceutics, 4, 255-280. Davidian, M. and Giltinan, D. M. (1995) Nonlinear Models for Repeated Measurement Data, Chapman & Hall (section 5.2.4, p. 134) Pinheiro, J. C. and Bates, D. M. (2000) Mixed-effects Models in S and S-PLUS, Springer.

Details

Each of the six subjects were given an intravenous injection of indomethacin.

Examples

data(Indometh)

TwoComp <- list(DiffEq=list(                         #Differential equations
                    dy1dt = ~ -(k12+k10)*y1+k21*y2 ,    #Compartment 1
                    dy2dt = ~ -k21*y2 + k12*y1),        #Compartment 2
                ObsEq=list(                          #Observation equation
                    c1 = ~ y1,
                    c2 = ~ 0),                           
                States=c("y1","y2"),                 #The names of the states in the sequence of DiffEq
                Parms=c("k12","k21","k10","start"),  #Parameter names
                LogParms=TRUE,                       #Estimate the logarithm of the parameters 
                Init=list("start",0),                   #Estimate the Initial states  
                JAC=TRUE,                            #Use the Jacobian             
                SEQ=FALSE)                           #Use sensitivity equations    


IndomethModel <- nlmeODE(TwoComp,Indometh)

Indometh.nlme <- nlme(conc ~ IndomethModel(k12,k21,k10,start,time,Subject),
   data = Indometh, fixed=k12+k21+k10+start~1, random = pdDiag(start+k12+k10~1), 
   start=c(k12=-0.05,k21=-0.15,k10=-0.10,start=0.70),
   control=list(msVerbose = TRUE))

plot(augPred(Indometh.nlme,level=0:1))