Agonist Spectrum
Haloperidol
Binds to and blocks D2 receptors while reducing dopamine activity and treating symptoms of psychosis (Fan et al., 2020).
Risperidone
Dopamine D2 receptors and Serotonin 5-HT2A receptors
Blocks D2 and 5-HT2A receptors, balancing dopamine and serotonin activity to treat symptoms of schizophrenia and bipolar disorder (Alvarez-Herrera et al., 2024).
Naloxone
Opioid receptors (primarily u-opioid receptors).
Inhibits opioid receptors by reversing the effects of opioid overdose (Cleveland Clinic, 2024).
Molecules that bind to the receptor, but do not activate it; thus blocking the action of agonists (Cleveland Clinic, 2024).
Antagonists
Pimavanserin
Serotonin 5-HT2A and Serotonin 5-HT2C (Muneta-Arrate et al., 2020).
Reduces the receptors constitutive activity to treat hallucinations and delusions associated with Parkinson's disease psychosis (Howland, 2016).
Molecules that bind to the receptor and indicate an opposite effect to the agonist (Grandy, 2016).
Mechanism: Binds to an inactive form of the receptor and reduce its inactive state (Qin et al., 2022).
Inverse Agonist
Brexpiprazole
Serotonin 5-HTA receptors
Dopamine D2 receptors
Acts as a partial agonist at D2 and 5-HTA receptors, and as an antagonist at 5-HT2A receptors, contributing to its antipsychotic and antidepressant effects (Hope et al., 2017).
Molecules that bind to the receptor, while producing a submaximal response compared to the full agonists (Berg & Clarke, 2019).
Mechanism: Binds to the receptor, but induces a less pronounced conformational change than the full agonists.
Partial Agonist
Medications/Targeted Receptors
Aripiprazole
Oxycodone
Opioid receptors(primarily u-opioid)
Acts as an agonist at the opioid receptor; binding to the opioid receptor and triggers pain relief (Edinoff et al., 2021).
Molecules with high efficay that binds to activate a receptor; producing maximum bilogical response (Berg & Clarke, 2019).
Mechanism: Binds to receptor, includes conformational change, activities downstream siginaling.
Full Agonist
