PharmPK Discussion - Question from a newbie!

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On 11 Nov 1999 at 09:57:02, Dylan Bulseco (bulseco.aaa.os.com) sent the message


I am trying to do some crude PK analysis using a general nonlinear curve
fitting program.  The models I am trying to implement are:

1. one- two- and three- exponentials
2. one- two- and three-exponentials with a time lag built in.
3. One compartment, 1st order input/output.
4. One compartment, 1st order input/output with time lag.
5. One compartment, Bolus IV, 1st order input
6. One compartment, Constant IV, 1st order input

Up to this point, we have only looked at exponentials and one-compartment
with 1st order input/output.  Are there any other (crude=simple!) models
that I should consider looking at?

Thanks,

Dylan

Dylan Bulseco, Ph.D.
UMASS Medical Center
Biotech IV, Room 321
377 Plantation St.
Worcester, MA 01605

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On 12 Nov 1999 at 20:48:01, David_Bourne (david.at.boomer.org) sent the message


[Two replies - db]

X-Sender: jelliffe.-at-.hsc.usc.edu
Date: Thu, 11 Nov 1999 08:47:00 -0800
To: PharmPK.aaa.boomer.org
From: Roger Jelliffe 
Subject:

Dear Dylan:

	Try the Adapt programs of Dave D'Argenio, especially for the time lag
models. You can get them free from his web site, which is

http://www.usc.edu/dept/biomed/BMSR

	Go to software. Look at the ADAPT programs. They do it all, very
generally, and easily. A very good and time-tested package.

Very best regards,

Roger W. Jelliffe, M.D. Professor of Medicine, USC
USC Laboratory of Applied Pharmacokinetics
2250 Alcazar St, Los Angeles CA 90033, USA
Phone (323)442-1300, fax (323)442-1302, email=  jelliffe.at.hsc.usc.edu
Our web site=  http://www.usc.edu/hsc/lab_apk
*****************
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Date: Fri, 12 Nov 1999 01:31:54 -0700 (MST)
X-Sender: ml11439.-at-.pop.goodnet.com
To: PharmPK.aaa.boomer.org
From: ml11439.-at-.goodnet.com (Michael J. Leibold)
Subject: Re: PharmPK Question from a newbie!

Hello Dr.Bulesco,

     It would be wise to not overlook nonlinear pharmacokinetics as
in the case of phenytoin. That is, Michaelis-Menten equations for
first order absorption, IV bolus and IV infusion:

     1) dc/dt= KaFDe-Kat - VmaxC/(Km + C)    [first order absorption]

     2) dc/dt=  - VmaxC/(Km + C)        [IV bolus]

     3) dc/dt= Ko/Vd- VmaxC/(Km + C)    [IV infusion]

     The method of fitting these equations can involve numerical
integration.

          Mike Leibold, PharmD, RPH
          ML11439.-at-.goodnet.com

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On 18 Nov 1999 at 19:44:24, ml11439.aaa.goodnet.com (Michael J. Leibold) sent the message


To Pharmacokinetic Discussion Group,

     I would like to report a slight error in equation #1 of
my last email to the discussion group. Equation 1 shuold have
read:

      1) dc/dt= [KaFDe-Kat]/Vd - VmaxC/(Km + C)    [first order absorption]

     That is, the Vd term should have appeared in this differential
equation.

          Mike Leibold, PharmD, RPh
          ML11439.aaa.goodnet.com
          Mike Leibold, PharmD, RPH
          ML11439.aaa.goodnet.com

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