Table 1.

Binding affinities of (+)‐MK‐801, phencyclidine, enantiomers of ketamine, and its metabolites to the NMDA receptor

Compounds	Ki (μM): Ebert et al.12	Ki (μM): Moaddel et al.13
(+)‐MK‐801	0.0019	0.0047
Phencyclidine	0.06	ND
(R,S)‐Ketamine	0.53	1.06
(S)‐Ketamine	0.3	0.69
(R)‐Ketamine	1.4	2.57
(S)‐Norketamine	1.7	2.25
(R)‐Norketamine	13	26.46
(2S,6S)‐Hydroxynorketamine	ND	21.19
(2R,6R)‐Hydroxynorketamine	ND	>100

ND, not determined.