NMDA receptor antagonist

NMDA receptor antagonists are a class of anesthetics that work to antagonize, or inhibit the action of, the N-Methyl-D-aspartate receptor (NMDAR). They are used as anesthetics for animals and for humans; the state of anesthesia they induce is referred to as dissociative anesthesia. There is evidence that NMDA receptor antagonists can cause a certain type of neurotoxicity or brain damage referred to as Olney's Lesions in rodents, although such damage has never been conclusively observed in primates like humans. Recent research conducted on primates suggests that, while very consistent and long-term ketamine use may be neurotoxic, acute use is not.[1][2]

Several synthetic opioids function additionally as NMDAR-antagonists, such as pethidine, methadone, dextropropoxyphene, tramadol and ketobemidone.

Some NMDA receptor antagonists, such as ketamine, dextromethorphan (DXM), phencyclidine (PCP), and nitrous oxide (N2O), are popular recreational drugs used for their dissociative, hallucinogenic, and euphoriant properties. When used recreationally, they are classified as dissociative drugs.