What is a significant factor in selecting a pharmacokinetic model?

Selecting a pharmacokinetic model involves understanding how a drug behaves in the body, which includes its distribution characteristics. Drug distribution refers to how the drug disperses throughout the body's tissues and fluids after administration. This is influenced by various factors such as solubility, permeability, and affinity for tissues, which are critical in predicting the drug's concentration in different compartments over time.

The distribution characteristics of a drug determine its bioavailability and the time it takes to reach the site of action. For example, drugs with high lipid solubility may rapidly distribute to fatty tissues, while those that are hydrophilic will predominantly remain in the bloodstream. The chosen pharmacokinetic model should accurately reflect these distribution dynamics to ensure proper dosing and efficacy, making drug distribution characteristics a pivotal factor in model selection.

Other factors, such as drug cost, patient age, and formulation type, while important in broader drug development and treatment decisions, do not directly influence the fundamental pharmacokinetic modeling of how a drug is distributed and metabolized in the body.