Mechanisms of General Anesthesia

Introduction

The branch of pharmacology that relates drug concentration to biologic effect is known as pharmacodynamics.

 Major goals of this area of study are determining the proper dose to administer to elicit the desired effect while avoiding toxicity. Although pharmacokinetics can be used to determine dosing requirements necessary to maintain a particular drug concentration, it is the relationship between drug concentration and effect that ultimately decides appropriate dosing. The ultimate goal is to maintain a drug concentration within the proper therapeutic window thereby avoiding toxicity while providing an adequate concentration of the drug to provide the desired effect.Most drug effects are induced by the interaction of a drug molecule with specific molecular structures in the body known as receptors.    

However, some drug effects are non–receptor mediated and are caused by the particular physical or chemical properties of the drug molecule. To firmly grasp the concepts of how effects, both desired and deleterious, are induced in the body by a drug molecule requires an understanding of where and how these molecules interact.