Reduction of dopamine D 2/3 receptor binding in the striatum after a single administration of esketamine, but not R-ketamine: a PET study in conscious monkeys

Abstract

R-ketamine appears to be a potent, long-lasting and safer antidepressant, relative to esketamine (S-ketamine), since it might be free of psychotomimetic side effects. Using [ 11 C]raclopride and positron emission tomography (PET), we investigated whether esketamine and R-ketamine can affect dopamine D 2/3 receptor binding in the conscious monkey brain. A single infusion of esketamine (0.5 mg/kg), but not R-ketamine (0.5 mg/kg), caused a reduction of binding availability of dopamine D 2/3 receptor in the monkey striatum. This study suggests that unlike to R-ketamine, esketamine can cause dopamine release in the striatum, and that its release might be associated with psychotomimetic effects of esketamine.

Abstract of "Reduction of dopamine D 2/3 receptor binding in the striatum after a single administration of esketamine, but not R-ketamine: a PET study in conscious monkeys" by Hashimoto K, Kakiuchi T, Ohba H et al., https://doi.org/10.1007/s00406-016-0692-7, used under its Creative Commons Attribution license (CC-BY); markup removed, otherwise unmodified.