7.11 : Multicompartment Models: Overview

Multicompartment models are mathematical constructs that depict how drugs are distributed and eliminated within the body. They segment the body into several compartments, symbolizing various physiological or anatomical areas connected through drug transfer processes such as absorption, metabolism, distribution, and elimination.

These models offer a more comprehensive representation of drug behavior in the body than one-compartment models. They accommodate the complexity of drug distribution, consider multiple elimination routes, and can describe drug behavior across different tissues or organs.

Certain assumptions underpin multicompartment models. These include immediate equilibrium in drug distribution between compartments, first-order elimination processes, and plasma drug concentration, which indicates drug concentration across all body tissues.

Multicompartment models have several applications in pharmacokinetics. They help predict drug concentration-time profiles, estimate parameters like clearance and volume of distribution and aid in formulating optimized drug dosing schedules. They prove especially useful for drugs exhibiting complex pharmacokinetics, such as those with wide tissue distribution or multiple elimination pathways.

In summary, multicompartment models offer a detailed and precise depiction of drug behavior within the body, enhancing our understanding and prediction of drug pharmacokinetics.