Physiological approach to clearance

Earlier in this chapter, the concept of an extraction ratio ( ) was introduced. Equation 4.8 shows that extraction ratio across an organ of elimination is equal to (Ca-Cv)/Ca, where Ca is the 

To provide further appreciation for the hepatic extraction ratio and its interrelationship with other pharmacokinetic parameters, we introduce the following physiological approach. 

From this we can calculate the plasma drug concentration entering the liver (Cp)  

The elimination rate is 2mols metabolized. Therefore, by still another equation, we can obtain  

If we are also told that, of the 10 molecules of drug presented to the liver in 1 s, 2 are metabolized and the other 8 escape metabolism, we can calculate that  

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