<unk> s are a class of anesthetics that work to antagonize, or inhibit the action of, the N-methyl d-aspartate<unk>  <unk> R). They are used as anesthesia for animals and, less commonly, for humans; the state of anesthesia they induce is referred to as dissociative anesthesia. However, there is evidence that<unk> s can cause a certain type of brain damage referred to as Olney's Lesions (in rodents).
Some<unk> s, such as ketamine and phencyclidine (PCP), are popular as recreational drugs for their hallucinogenic properties. When used recreationally, they are classified as dissociative drugs. Because some users use them for spiritual reasons, these recreational<unk> s are sometimes considered entheogens.
NMDA receptor antagonist
Nicotinic antagonist
Serotonin antagonist
Dopamine antagonist
5-HT3 antagonist
Acetylcholinesterase inhibitor
Dopamine agonist
Muscarinic antagonist