iNTRAVENOUS VS. INTRA-ARTERIAL SAMPLING

Hi everyone; Does anyone have experience modeling data where some samples were drawn intravenously, while others (sometimes even within a given patient) were drawn from an arterial line? There are no samples drawn simultaneously from both lines, unfortunately. (image/jpeg attachment: 01-part)

Hi everyone; Does anyone have experience modeling data where some samples were drawn intravenously, while others (sometimes even within a given patient) were drawn from an arterial line? There are no samples drawn simultaneously from both lines, unfortunately. <<image/jpeg>>

Hello Mike I have seen a case where effect compartment concept was used to describe the venous and arterial concentrations in a patient. Atul Venkatesh Atul Bhattaram Pharmacometrics US Food and Drug Administration "The contents of this message are mine personally and do not necessarily reflect any position of the Government or the Food and Drug Administration." ________________________________

Hi Michael, I think this reference may be useful in answering your question: Darwish M, Kirby M, Robertson P Jr, Hellriegel E, Jiang JG. Comparison of equivalent doses of fentanyl buccal tablets and arteriovenous differences in fentanyl pharmacokinetics. Clin Pharmacokinet. 2006;45(8):843-50. Regards, *Murad Melhem, PhD* *Assistant Director PK/PD* *Cognigen Corporation*

Hi Michael, Arterial versus venous sampling could be important for anesthesia or similar problems where the time scale of interest goes down to half-a-minute or so. I did some modeling (venous and arterial sampling fro the same saubjects) that indicated that the venous concentration was delayed by 1-2 minutes relative to the arterial ones. Also, for IV bolus, Cmax arterial was higher than Cmax venous (Tmax venous was later than Tmax arterial). The difference was important during the first few minutes after the IV bolus when the rate of concentration changes was high; then, the difference gradually declined. Apart from the times when the rate of concentration changes was very high (concentration changed significantly within 1-2 minutes) the difference between arterial and venous concentrations was negligible. Leonid -------------------------------------- Leonid Gibiansky, Ph.D. President, QuantPharm LLC web: www.quantpharm.com e-mail: LGibiansky at quantpharm.com tel: (301) 767 5566 [EMAIL PROTECTED] wrote: > Hi everyone; > > Does anyone have experience modeling data where some samples were drawn intravenously, while others (sometimes even within a given patient) were drawn from an arterial line? There are no samples drawn simultaneously from both lines, unfortunately.

Hi Michael, You may also look at these references 1. Tuk B, van Gool T, Danhof M. Mechanism-based pharmacodynamic modeling of the interaction of midazolam, bretazenil, and zolpidem with ethanol. J Pharmacokinet Pharmacodyn. Jun 2002;29(3):235-250. 2. Tuk B, Danhof M, Mandema JW. The impact of arteriovenous concentration differences on pharmacodynamic parameter estimates. J Pharmacokinet Biopharm. Feb 1997;25(1):39-62. Sebastien [EMAIL PROTECTED] a écrit : Hi everyone; Does anyone have experience modeling data where some samples were drawn intravenously, while others (sometimes even within a given patient) were drawn from an arterial line? There are no samples drawn simultaneously from both lines, unfortunately.