OSU 6162

OSU-6162 (PNU-96391) is a compound which acts as a partial agonist at both dopamine D₂ receptors and 5-HT_2A receptors. It acts as a dopamine stabilizer in a similar manner to the closely related drug pridopidine, and has antipsychotic, anti-addictive and anti-Parkinsonian effects in animal studies. Both enantiomers show similar activity but with different ratios of effects, with the (S) enantiomer (–)-OSU-6162 that is more commonly used in research, having higher binding affinity to D₂ but is a weaker partial agonist at 5-HT_2A, while the (R) enantiomer (+)-OSU-6162 has higher efficacy at 5-HT_2A but lower D₂ affinity.