Back to the Top
This is for a colleague of mine.
Any suggestions or comments can be directed to this list or to me.
Thanks.
Vinay
Email:Vinay.Desai.at.Americas.Nycomed.com
********************************************************************************
**
Objective: To model the effect of changes in intravenous rate of
administration on blood drug concentration vs. time profile.
********************************************************************************
**
A drug is administered by rapid bolus (rate defined) at several dosages
and blood collected for analysis of test article concentration at several
intervals following dosing, and the blood drug concentration vs. time
profile defined. Based upon this data, I would like to model the blood
drug concentration vs. time profiles for the same (or lower) dosages
administered at different rates (slower or faster). I'm looking for a
pharmacokinetic model which will permit me to model the effects of
dosage, dosage rate, and blood drug concentration vs. time.
Dosage Rate C1 C2 C3 C4 C5 C6 C7
25
75
150
Back to the Top
I may be missing something in your question but any PK model for an
infusion (apart from those parameterised in the antique A,alpha,B,beta style)
will allow the dose (or dose rate) and duration to be defined as part of
the model and it should be straightforward to estimate PK parameters
from your data and subsequently simulate profiles with different doses
and input rates.
--
Nick Holford, Dept Pharmacology & Clinical Pharmacology
University of Auckland, Private Bag 92019, Auckland, New Zealand
email:n.holford.aaa.auckland.ac.nz tel:+64(9)373-7599x6730 fax:373-7556
http://www.phm.auckland.ac.nz/Staff/NHolford/nholford.html
Back to the Top
>PharmPK - Discussions about Pharmacokinetics
> Pharmacodynamics and related topics
>
>This is for a colleague of mine.
>
>Any suggestions or comments can be directed to this list or to me.
>Thanks.
>Vinay
>
>Email:Vinay.Desai.-a-.Americas.Nycomed.com
>***************************************************************************
*****
>**
>Objective: To model the effect of changes in intravenous rate of
>administration on blood drug concentration vs. time profile.
>***************************************************************************
*****
>**
>A drug is administered by rapid bolus (rate defined) at several dosages
>and blood collected for analysis of test article concentration at several
>intervals following dosing, and the blood drug concentration vs. time
>profile defined. Based upon this data, I would like to model the blood
>drug concentration vs. time profiles for the same (or lower) dosages
>administered at different rates (slower or faster). I'm looking for a
>pharmacokinetic model which will permit me to model the effects of
>dosage, dosage rate, and blood drug concentration vs. time.
>
>Dosage Rate C1 C2 C3 C4 C5 C6 C7
>
>25
>75
>150
>
You need a model that is a good description of initial bolus kinetics to do
this. I addressed these issues in a recent paper:
Upton RN. A model of the first pass passage of drugs from their intravenous
injection site to the
heart - parameter estimates for lignocaine. Br J Anaesth 77: 764-772 (1996)
You also might like to look at:
Wada DR, Ward DS. The hybrid model: a new pharmacokinetic model for
computer-controlled infusion pumps. IEEE Transcripts of Biomedical
Engineering 1994; 41: 134-42.
Krejcie TC, Henthorn TK, Shanks CA, Avram MJ. A recirculatory
pharmacokinetic model describing the circulatory mixing, tissue distribution
and
elimination of antipyrine in the dog. Journal of Pharmacology and
Experimental
Therapeutics 1994; 269: 609-616.
I hope these references are of use.
Regards, Richard Upton
---------
Dr Richard Upton
Senior Hospital Scientist/Senior Lecturer
Department of Anaesthesia and Intensive Care
Royal Adelaide Hospital/University of Adelaide
SA 5005 Australia
rupton.aaa.health.adelaide.edu.au
Back to the Top
> This is for a colleague of mine.
>
> Any suggestions or comments can be directed to this list or to me.
> Thanks.
> Vinay
>
> Email:Vinay.Desai.at.Americas.Nycomed.com
>
>********************************************************************************
> **
> Objective: To model the effect of changes in intravenous rate of
> administration on blood drug concentration vs. time profile.
>
>********************************************************************************
> **
> A drug is administered by rapid bolus (rate defined) at several dosages
> and blood collected for analysis of test article concentration at several
> intervals following dosing, and the blood drug concentration vs. time
> profile defined. Based upon this data, I would like to model the blood
> drug concentration vs. time profiles for the same (or lower) dosages
> administered at different rates (slower or faster). I'm looking for a
> pharmacokinetic model which will permit me to model the effects of
> dosage, dosage rate, and blood drug concentration vs. time.
Dear colleague,
I would like to draw your attention to our software package
CXT (see e.g. our recent paper in Comput.Meth.Programs Biomed., 51,
1996, 183-192). A version of the package is available at:
http://www.cpb.uokhsc.edu/pkin/pkin.html, option SOFTWARE.
The package can be used e.g.:
-to define the pharmacokinetic system in an "input-output" form,
where an infusion, defined by its dosage rate and duration, may
be the input, and a blood concentration profile may be the output;
-to determine the model of this system and the model of the output
of this system, i.e. the model describing the blood concentration
profile during and after infusion;
-to determine the weighting function of this system in a numerical
and/or analytical form;
-to compare two weighting functions corresponding to two different
pharmacokinetic systems.
Maria Durisova
Ladislav Dedik
PharmPK Discussion List Archive Index page
Copyright 1995-2010 David W. A. Bourne (david@boomer.org)