1 minute read
May 29, 2019

PK Cheat Sheet

Drug Hunter Team

This article contains a pharmacokinetics reference table ("PK cheat sheet") with common cross-species physiological parameters relevant to PK, including animal size, liver blood flow, kidney blood flow, and body volumes.

When interpreting compound pharmacokinetic (PK) data, it's helpful to have reference values to compare experimental data to. A compound with a measured rat clearance value of 0.3 L/hr/kg, for example, is being removed at a slow rate relative to rat liver blood flow (3.3 L/hr/kg), indicating that the compound is not rapidly metabolized or excreted upon passage through the liver. A compound with a suprahepatic rat clearance value of 6.6 L/hr/kg, on the other hand, is apparently being removed faster than blood travels through the liver, suggesting that the either the liver is not the only organ contributing to compound removal, or that the compound is unstable in the blood.

Here is a physiological parameters reference table I've found helpful as a "PK cheat sheet" over the years for interpreting PK data. (This was given to me by my first supervisor, Hilary Beck, but I think this might be the original data compilation: Davies, B.; Morris, T. "Physiological Parameters in Laboratory Animals and Humans." Pharm. Res. 1993, 10, 1093-1095. doi: 10.1023/A:1018943613122) I don't know why some companies prefer sharing data in L/hr/kg vs. mL/min/kg units, but it's helpful for paper-reading to just memorize there are ~17 mL/min in a L/hr. Enjoy this PK cheat sheet!

If you found this useful, you may also enjoy our Practical PK Calculators.

Update 6/19/23: Readers on LinkedIn shared that a more recent set of values with higher rodent blood flow values (by 20-33%) was published in 2011 by a PhRMA working group, and a survey confirming these general values across the industry was published in 2022 by the IQ Consortium Human PK Prediction Working Group based on a survey of various industry groups.

Explore drughunter.com/resource for more helpful reference material.


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