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. However, adolescent cynomolgus monkeys that were injected daily for six months with the non-competitive NMDA antagonist ketamine showed decreased locomotor activity and increased apoptosis of cells in their prefrontal cortices.
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 anesthesia for animals and, less commonly, for humans; the state of anesthesia they induce is referred to as dissociative anesthesia. Memantine is an uncompetitive NMDA channel blocker. Memantine is the first in a novel class of Alzheimer's disease medications acting on the glutamatergic system by blocking NMDA glutamate…
Ketamine is a drug used in human and veterinary medicine, primarily for the induction and maintenance of general anesthesia, usually in combination with a sedative. Pharmacologically, ketamine is classified as an NMDA receptor antagonist.
Phencyclidine (a complex clip of the chemical name 1-(1-phenylcyclohexyl)piperidine), (PCP) and known colloquially as angel dust or wet, is a recreational dissociative drug. Formerly used as an anesthetic agent, PCP exhibits both hallucinogenic and neurotoxic effects. PCP is an NMDA receptor antagonist.PCP is an NMDA receptor antagonist. PCP, like ketamine, also acts as a D2 receptor partial agonist. D2 receptor antagonists (such as haloperidol) can be used in the treatment of PCP psychosis.
Memantine is approved for the treatment of moderate to severe Alzheimer’s. It is an N-methyl-D-aspartate (NMDA) receptor antagonist. The NMDA receptor is one of several receptors located on the postsynaptic neurons in the hippocampus, which receive transmissions from the neurotransmitter glutamate. Glutamate is a major excitatory neurotransmitter that is associated with learning and memory, used by more than 80% of the neurons in the brain.
Biochemistry of Memantine: The drug belongs to a class of drugs called NMDA receptor antagonists, which reduce certain types of brain activity by binding to NMDA receptors on brain cells and blocking the activity of the neurotransmitter glutamate. At normal levels, glutamate aids in memory and learning, but if levels are too high, glutamate appears to overstimulate nerve cells, killing them through excitotoxicity.