Longnecker's Anesthesiology > Part 4. Managing Anesthesia Care > Section C. Anesthesia Drugs and Drug Delivery Systems > Chapter 39. Principles of Pharmacokinetics and Pharmacodynamics: Applied Clinical Pharmacology for the Practitioner Ken B. Johnson, MD, and Talmage D. Egan, MD

Key Points

"1. The ultimate goal of pharmacokinetic–pharmacodynamic study is accurate prediction of the time course and magnitude of drug effect so that the clinician can answer a very simple and important question: "What is the appropriate dosing scheme for my patient?"

2. Pharmacokinetics, often thought of as "what the body does to the drug," is the study of the relationship between the drug dose and the drug concentrations that are produced over time.

3. Pharmacodynamics, often thought of as "what the drug does to the body," is the study of the relationship between the drug concentration and the drug effects that are produced.

4. Pharmacokinetic–pharmacodynamic models can be constructed that characterize drug behavior. These models are mathematical expressions of the relationship between drug dose and concentration (pharmacokinetics) and drug concentration and effect (pharmacodynamics). The models are composed of individual parameters (e.g., clearance, distribution volume, effective concentration for 50% of maximal effect, etc.). Because of the complex interaction of the parameters, drawing conclusions about drug behavior from a single parameter is difficult.

5. Because it is a mathematically based discipline, pharmacokinetics–pharmacodynamics is a distinctly unpopular subject among clinical anesthesiologists. This unpopularity..."