ADMEPKPD

ADMEPKPD is an integrated framework that combines absorption, distribution, metabolism, and excretion with pharmacokinetics and pharmacodynamics to describe and predict how a drug moves through the body and what effect it produces. ADME describes how the body handles the drug; PK characterizes time-dependent drug concentrations; PD characterizes the concentration–effect relationship. In practice, ADMEPKPD uses mathematical models to connect physiological processes to drug response.

Modeling approaches include compartmental PK models, physiologically based pharmacokinetic (PBPK) models, and PK/PD models that link concentration to response. Population PK/PD uses data from diverse individuals to quantify variability. IVIVE translates in vitro data to in vivo predictions, and transporter/enzyme interactions and drug–drug interactions are incorporated to refine predictions. These models may include nonlinear effects, saturation, or tolerance.

Applications include dose regimen design, optimization of exposure and response, identification of safety thresholds, and support for regulatory submissions. They are used in preclinical-to-clinical extrapolation, early decision making, and post-market surveillance. Data sources include in vitro ADME assays, animal and human PK data, biomarker readouts, and pharmacodynamic endpoints. Model validation and sensitivity analysis are essential to assess reliability and guide decisions.

Limitations include biological complexity, interindividual variability, disease-state effects, and uncertainty in extrapolation. Ongoing data collection and model refinement, along with transparent reporting, improve predictive performance and support risk assessment in drug development.