Plasma and tissue binding of psychotropic drugs

TLDR: The large number of binding studies carried out in recent years rather reflects the fact that there is a multitude of additional drug binding sites, such as metabolic and transport sites, as well as a variety of non-specific sites.

Abstract: Most pharmacological actions are the result of binding of drug molecules to specific receptors. However, only in a few instances are these receptors known entities which lend themselves to investigation. Thus, the large number of binding studies carried out in recent years rather reflects the fact that there is a multitude of additional drug binding sites, such as metabolic and transport sites, as well as a variety of non-specific sites. The latter are also called ‘silent receptors’ or ‘sites of loss’ since their occupation does not result in pharmacological actions. However, this kind of binding is believed to be a major determinant of pharmacokinetics which again modifies pharmacodynamics.