NMDA receptor modulators (
glutamate
Glutamic acid (symbol Glu or E; known as glutamate in its anionic form) is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a Essential amino acid, non-essential nutrient for humans, meaning that ...
modulators) are a new form of
antipsychotic
Antipsychotics, previously known as neuroleptics and major tranquilizers, are a class of Psychiatric medication, psychotropic medication primarily used to manage psychosis (including delusions, hallucinations, paranoia or disordered thought), p ...
that are in Phase II FDA studies. The first compound studied was
glycine
Glycine (symbol Gly or G; ) is an amino acid that has a single hydrogen atom as its side chain. It is the simplest stable amino acid. Glycine is one of the proteinogenic amino acids. It is encoded by all the codons starting with GG (G ...
which was hypothesized by Daniel Javitt after observation that people with
phencyclidine
Phencyclidine or phenylcyclohexyl piperidine (PCP), also known in its use as a street drug as angel dust among other names, is a dissociative anesthetic mainly used recreationally for its significant mind-altering effects. PCP may cause hall ...
(PCP)-induced
psychosis
In psychopathology, psychosis is a condition in which a person is unable to distinguish, in their experience of life, between what is and is not real. Examples of psychotic symptoms are delusions, hallucinations, and disorganized or inco ...
were lacking in
glutamate
Glutamic acid (symbol Glu or E; known as glutamate in its anionic form) is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a Essential amino acid, non-essential nutrient for humans, meaning that ...
transmission. (PCP is an
NMDA receptor antagonist
NMDA receptor antagonists are a class of drugs that work to receptor antagonist, antagonize, or inhibit the action of, the NMDA, ''N''-Methyl-D-aspartate receptor (NMDA receptor, NMDAR). They are commonly used as anesthetics for humans and anima ...
that blocks glutamate.) In giving glycine to people with PCP-induced psychosis a recovery rate was noted. From there, it was hypothesized that people with psychosis from
schizophrenia
Schizophrenia () is a mental disorder characterized variously by hallucinations (typically, Auditory hallucination#Schizophrenia, hearing voices), delusions, thought disorder, disorganized thinking and behavior, and Reduced affect display, f ...
would benefit from increased glutamate transmission and glycine was added with strong recovery rates noted especially in the area of negative and cognitive symptoms. Glycine, however, sporadic results aside (dose 60 g/day or 0.8 g/kg, approximately the amount in 300 g of gelatin powder or two kilograms of sunflower seeds
) remains an adjunct
antipsychotic
Antipsychotics, previously known as neuroleptics and major tranquilizers, are a class of Psychiatric medication, psychotropic medication primarily used to manage psychosis (including delusions, hallucinations, paranoia or disordered thought), p ...
and an unworkable compound. However, the
Eli Lilly and Company
Eli Lilly and Company, Trade name, doing business as Lilly, is an American multinational Medication, pharmaceutical company headquartered in Indianapolis, Indiana, with offices in 18 countries. Its products are sold in approximately 125 count ...
study drug
LY-2140023 is being studied as a primary
antipsychotic
Antipsychotics, previously known as neuroleptics and major tranquilizers, are a class of Psychiatric medication, psychotropic medication primarily used to manage psychosis (including delusions, hallucinations, paranoia or disordered thought), p ...
and is showing strong recovery rates, especially in the area of negative and cognitive symptoms of
schizophrenia
Schizophrenia () is a mental disorder characterized variously by hallucinations (typically, Auditory hallucination#Schizophrenia, hearing voices), delusions, thought disorder, disorganized thinking and behavior, and Reduced affect display, f ...
.
Tardive dyskinesia
Tardive dyskinesia (TD) is an iatrogenic disorder that results in involuntary repetitive body movements, which may include grimacing, sticking out the tongue or smacking the lips, which occurs following treatment with medication. Additional mo ...
,
diabetes
Diabetes mellitus, commonly known as diabetes, is a group of common endocrine diseases characterized by sustained high blood sugar levels. Diabetes is due to either the pancreas not producing enough of the hormone insulin, or the cells of th ...
and other standard complications have not been noted:
Treatment with LY2140023, like treatment with olanzapine, was safe and well-tolerated; treated patients showed statistically significant improvements in both positive and negative symptoms of schizophrenia compared to placebo (P = 0.001 at week 4). Notably, patients treated with LY-2140023 did not differ from placebo-treated patients with respect to prolactin elevation, extrapyramidal symptoms or weight gain. These data suggest that mGlu2/3 receptor agonists have antipsychotic properties and may provide a new alternative for the treatment of schizophrenia.
Other NMDA receptor modulators are being studied and this modality of treatment may once approved as
antipsychotic
Antipsychotics, previously known as neuroleptics and major tranquilizers, are a class of Psychiatric medication, psychotropic medication primarily used to manage psychosis (including delusions, hallucinations, paranoia or disordered thought), p ...
medications gradually replace the current (dopaminergic) antipsychotics.
References
External links
Antipsychotics, *
NMDA receptor agonists
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