Bioequivalence and Bioavailability Forum

Hi all,

I am getting some weird results when I tried to use PKNCA...

1) I followed the instructions from the following link and the AUC calculated from the PKNCA example was close to my Excel AUClast calculation. PKNCA's AUClast value was 12.9965842 and my excel calculated value (using the AUC equation) was 13.05000. The values were not far off from each others.

PKNAC example

2) I modified the PKNCA codes from the example above to calculate PK parameters for the following dataset. PKNCA's AUClast value was 5997.7885480, but my excel calculated value was 6825.422.???? I am not sure what went wrong. Below is the dataset. Can anyone give it a try and let me know?

Here are the codes I updated from the link above and used to run the computation (I didn't include the ggplot routine here since that part ran fine)

suppressPackageStartupMessages({
library(PKNCA)
library(dplyr)
library(cowplot)
library(knitr)
library(ggplot2)
})
scale_colour_discrete <- scale_colour_hue
scale_fill_discrete <- scale_fill_hue
my_conc <- data.frame(read.csv("Data.csv"))
my_conc$BLQ <- my_conc$Concentration == 0
my_conc$measured <- TRUE

conc_obj <- PKNCAconc(my_conc, Concentration~Time|Subject)
data_obj <- PKNCAdata(data.conc=conc_obj,
                      intervals=data.frame(start=0, end=72,
                      auclast=TRUE, aucinf.pred=TRUE, aucinf.obs=TRUE))

results_obj <- pk.nca(data_obj)

kable(as.data.frame(results_obj))

Here is the DATA.CSV

Subject   Time   Concentration
273      0           0
273      0.5       307.838
273      1         467.58
273      2         439.886
273      4         489.621
273      8         306.011
273     24          54.424
273     48          3.628
273     72          0

Thx
J