Full agonists, partial agonists and inverse agonists

An agonist is a ligand that binds to a receptor and alters the receptor state resulting in a biological response. A full agonist reaches the maximal response capability of the system, and a partial agonist does not (even at full receptor occupancy). A partial agonist acts as an antagonist in the presence of a full agonist (if they compete for the same receptors). An inverse agonist is a ligand that by binding to receptors reduces the fraction of them in an active conformation. Spare receptors are said to exist wherever a full agonist can cause a maximum response when occupying only a fraction of the total receptor population.

Drug-Receptor Interaction: Agonist - Concept, Pharmacology

Rational drug design of CB2 receptor ligands: from 2012 to 2021 - RSC Advances (RSC Publishing) DOI:10.1039/D2RA05661E

Mechanisms of Drug Action - ScienceDirect

Agonism and antagonism - Physics, Pharmacology and Physiology for Anaesthetists

No Evidence for Functional Selectivity of Proxyfan at the Human Histamine H3 Receptor Coupled to Defined Gi/Go Protein Heterotrimers

Rate of change of blood concentrations is a major determinant of the pharmacodynamics of midazolam in rats - Cleton - 1999 - British Journal of Pharmacology - Wiley Online Library

Making Sense of Pharmacology: Inverse Agonism and Functional Selectivity. - Abstract - Europe PMC

Agonist, Partial Agonist, Antagonist and Inverse Agonist for Receptors

Drug Receptor Binding - an overview

PDF) 7-Oxo-[1,4]oxazino[2,3,4-ij]quinoline-6-carboxamides as Selective CB2 Cannabinoid Receptor Ligands: Structural Investigations around a Novel Class of Full Agonists

GraphPad Prism 10 Curve Fitting Guide - Equation: Operational model - Partial agonist