Pharmacokinetic concepts revisited--basic and applied.

Area of Science:

• Pharmacology
• Critical Care Medicine
• Pharmacometrics

Background:

• Critically ill patients experience pathophysiological changes affecting drug concentrations.
• Altered pharmacokinetics (PK) in these patients necessitates dose adjustments for optimal therapy.
• Understanding PK principles is crucial for improving drug dosage guidelines in critical care.

Purpose of the Study:

• To define key PK parameters relevant to critically ill patients.
• To review PK analysis methods in research and clinical settings.
• To highlight advanced modeling techniques for optimizing drug dosing.

Main Methods:

• Overview of traditional PK analysis methods (non-compartmental, two-stage).
• Introduction to Population PK (POPPK) modeling for analyzing sparse and rich datasets.
• Discussion of Bayesian approaches for optimizing dosing in clinical practice.

Main Results:

• Traditional methods require intensive sampling and do not fully capture inter-individual variability.
• POPPK modeling accurately estimates between-subject variability (BSV) and explores covariate relationships.
• Bayesian methods, combined with POPPK, offer efficient and individualized dosing solutions.

Conclusions:

• POPPK modeling provides robust estimates of PK variability in critical care.
• Bayesian approaches facilitate timely and individualized drug dosing in clinical settings.
• Integrated use of POPPK, Bayesian methods, and study design is recommended for enhanced critical care pharmacotherapy.