(R)-Ketamine (arketamine) may have utility as a rapidly acting antidepressant. While (R)-ketamine has lower potency than (R,S)-ketamine to inhibit NMDA receptors in vitro, the extent to which (R)-ketamine shares the NMDA receptor-mediated adverse effects of (R,S)-ketamine in vivo has not been fully characterised. Furthermore, (R)-ketamine is metabolised to (2R,6R)-hydroxynorketamine (HNK),...
Significance Despite available medications for depression, currently approved antidepressants take months to exert therapeutic effects, and ∼30% of patients remain treatment resistant. In contrast, a single subanesthetic dose of ketamine exerts rapid (within hours) and sustained antidepressant actions. Preclinical studies indicate that the ketamine metabolite ( 2R , 6R )-hydroxynorketamine [(...