Arketamine

Arketamine

Clinical data
ATC code	None
Legal status
Legal status	AU: S8 (Controlled) CA: Schedule I UK: Controlled Drug US: Schedule III UN: Unscheduled
Identifiers
IUPAC name (R)-2-(2-Chlorophenyl)-2-(methylamino)cyclohexanone
CAS Number	33643-49-1
PubChem CID	644025
ChemSpider	559099
UNII	Y2RI13H7VW
Chemical and physical data
Formula	C13H16ClNO
Molar mass	237.725 g/mol
3D model (Jmol)	Interactive image
SMILES CNC1(CCCCC1=O)C2=CC=CC=C2Cl
InChI InChI=1S/C13H16ClNO/c1-15-13(9-5-4-8-12(13)16)10-6-2-3-7-11(10)14/h2-3,6-7,15H,4-5,8-9H2,1H3/t13-/m1/s1 Key:YQEZLKZALYSWHR-CYBMUJFWSA-N

Arketamine, also (R)-ketamine or (R)-(−)-ketamine, is the (R)-(−) enantiomer of ketamine. Similarly to racemic ketamine and esketamine, the S(+) enantiomer of ketamine, arketamine is biologically active; however, it is less potent as an NMDA receptor antagonist and anesthetic and thus has never been approved or marketed for clinical use as an enantiopure drug.

Relative to esketamine, arketamine possesses 4–5 times lower affinity for the PCP site of the NMDA receptor. In accordance, arketamine is significantly less potent than racemic ketamine and especially esketamine in terms of anesthetic, analgesic, and sedative-hypnotic effects. Racemic ketamine has weak affinity for the sigma receptor, where it acts as an agonist, whereas esketamine binds negligibly to this receptor, and so the sigma receptor activity of racemic ketamine lies in arketamine. It has been suggested that this action of arketamine may play a role in the hallucinogenic effects of racemic ketamine and that it may be responsible for the lowering of the seizure threshold seen with racemic ketamine. Esketamine inhibits the dopamine transporter about 8-fold more potently than does arketamine, and so is about 8 times more potent as a dopamine reuptake inhibitor. Arketamine and esketamine possess similar potency for interaction with the muscarinic acetylcholine receptors.