(edited by daryazyatina on 2017-07-25 15:32)
Posting: # 17608
Good day, guys!
I have some data about concentration and time of this concentration from the literature data. I want to compare the data from WinNonLin with data from RStudio.
This .csv file I imported in RStudio.
and this code I used to calculate the pharmacokinetic parameters:
I need calculate elimination constant with time points from 5h to 24h.
After all RStudio calculate pharmacokinetic parameters BUT the elimination constant is incorrectly calculated.
What I do wrong?
Edit: Category changed; see also this post #1. [Helmut]
Posting: # 17611
» I want to compare the data from WinNonLin with data from RStudio.
» timeUnit = "h",
» doseUnit = "g",
» adminType = "extravascular",
» doseType = "ns",
» method = "linear",
» printOut = FALSE,
» LambdaExclude = c(0,0.33,0.66,1,1.33,1.66,2,2.5,3,3.5,4)
I used this code in the R-console
and got matching results in Phoenix/WinNonlin 7.0 with its automatic method of selecting the time range for λz (i.e., maximizing R²adj):
Hence, seemingly the argument
» I need calculate elimination constant with time points from 5h to 24h.
Why do you want to do that?
You would go from a good and reasonable fit (distribution/elimination)
to a completely wrong one:
» After all RStudio calculate pharmacokinetic parameters BUT the elimination constant is incorrectly calculated.
In this case it is good that
BTW, I strongly recommend to abandon the lousy linear trapezoidal method (positively biased AUC for decreasing concentrations). Better to use the argument
The quality of responses received is directly proportional to the quality of the question asked. ☼
Posting: # 17616
Thank you, Helmut, for your answer.
» Hence, seemingly the argument
I have the same problems with using
I will write to the authors. I hope they fix this problem.