Back to the Top
The following message was posted to: PharmPK
Hello!
I am a very recent PK/PD monitor and because of that, I have terrible
problems in my first experience.
I have to study a new drug and there are various aspects with it which
I can't explain.
First of all, the graphs, I think, are indicating that the drug has a
enterohepatic circulation, but other studies indicate that it is
extremely degradated, so, could it be another explanation with the
second peak on the chart?
Another question is I have used Nonmem until now, but now I have to
use WNL. I don't know anything about the PK of the drug, so I have
done a Non-Compartimental Analysis. With the preliminary results that
I have obtained what is it the second step that I should do?
Theoretically I have just know the half-life, the apparent volume and
now, how can I define if my drug has a mono-bicompartimental kinetics,
etc..
Thank you very much in advance
Back to the Top
The following message was posted to: PharmPK
Potential reasons for a second peak:
-Slow-release formulation
-botched formulation (incomplete dissolution in stomach?)
-inter-individual variation
-sample switching
-food effects
-different pharmacokinetics between R- and S- enantiomers (does your
drug have chiral centres?)
-random chance
-cosmic rays
Or, what if the assay is also mistakenly detecting the metabolite in
addition to the parent? Then it would appear as a second peak.
My favourite reason, though, is cosmic rays.
-Dave
Back to the Top
Dear Dave,
One more reason could be enterohepatic re-circulation.
Beta blockers.
Want to post a follow-up message on this topic?
If this link does not work with your browser send a follow-up message to PharmPK@boomer.org with "Starting PK analysis" as the subject | Support PharmPK by using the |
Copyright 1995-2011 David W. A. Bourne (david@boomer.org)