# Chapter 4 - Page 8

## Diagram Illustrating the Relationship between Clearance, Volume and Half-life

Explore the relationship between extraction ratio, blood flow, clearance, volume and elimination half-life. The hepatic (E(H)) and renal (E(R)) extration ratios may be varied between 0 and 100%. The apparent volume of distribution for different drugs may vary from a low of about 10 L up to 1000 L or more. The interrelationship between these parameters influence the overall elimination of a drug.
The derivation of these relationships include extraction ratio, clearance, elimination rate constant and half-life.

**Equation 4.3.1 Hepatic Extration Ratio**

**Equation 4.3.2 Renal Extration Ratio**

**Equation 4.3.3 Hepatic Clearance**

**Equation 4.3.4 Renal Clearance**

**Equation 4.3.5 Total Body Clearance**

**Equation 4.3.6 Elimination Rate Constant**

**Equation 4.3.7 Elimination Half-life**

Adjust the Extraction Ratio(s) and apparent Volume of Distribution to explore these relationships.

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