In pharmacology, partial agonists are drugs that bind to and activate a given receptor, but have only partial efficacy at the receptor relative to a full agonist. They may also be considered ligands which display both agonistic and antagonistic effects—when both a full agonist and partial agonist are present, the partial agonist actually acts as a competitive antagonist,[ citation needed] competing with the full agonist for receptor occupancy and producing a net decrease in the receptor activation observed with the full agonist alone. [1] Clinically, partial agonists can be used to activate receptors to give a desired submaximal response when inadequate amounts of the endogenous ligand are present, or they can reduce the overstimulation of receptors when excess amounts of the endogenous ligand are present. [2]
Some currently common drugs that have been classed as partial agonists at particular receptors include buspirone, aripiprazole, buprenorphine, nalmefene and norclozapine. Examples of ligands activating peroxisome proliferator-activated receptor gamma as partial agonists are honokiol and falcarindiol. [3] [4] Delta 9-tetrahydrocannabivarin ( THCV) is a partial agonist at CB2 receptors and this activity might be implicated in ∆9-THCV-mediated anti-inflammatory effects. [5] Additionally, Delta-9-Tetrahydrocannabinol ( THC) is a partial agonist at both the CB1 and CB2 receptors, with the former being responsible for its psychoactive effects.
In pharmacology, partial agonists are drugs that bind to and activate a given receptor, but have only partial efficacy at the receptor relative to a full agonist. They may also be considered ligands which display both agonistic and antagonistic effects—when both a full agonist and partial agonist are present, the partial agonist actually acts as a competitive antagonist,[ citation needed] competing with the full agonist for receptor occupancy and producing a net decrease in the receptor activation observed with the full agonist alone. [1] Clinically, partial agonists can be used to activate receptors to give a desired submaximal response when inadequate amounts of the endogenous ligand are present, or they can reduce the overstimulation of receptors when excess amounts of the endogenous ligand are present. [2]
Some currently common drugs that have been classed as partial agonists at particular receptors include buspirone, aripiprazole, buprenorphine, nalmefene and norclozapine. Examples of ligands activating peroxisome proliferator-activated receptor gamma as partial agonists are honokiol and falcarindiol. [3] [4] Delta 9-tetrahydrocannabivarin ( THCV) is a partial agonist at CB2 receptors and this activity might be implicated in ∆9-THCV-mediated anti-inflammatory effects. [5] Additionally, Delta-9-Tetrahydrocannabinol ( THC) is a partial agonist at both the CB1 and CB2 receptors, with the former being responsible for its psychoactive effects.