Fenobam is an

imidazole Imidazole (ImH) is an organic compound with the formula C3N2H4. It is a white or colourless solid that is soluble in water, producing a mildly alkaline solution. In chemistry, it is an aromatic heterocycle, classified as a diazole, and has non ...

derivative developed by McNeil Laboratories in the late 1970s as a novel

anxiolytic An anxiolytic (; also antipanic or antianxiety agent) is a medication or other intervention that reduces anxiety. This effect is in contrast to anxiogenic agents which increase anxiety. Anxiolytic medications are used for the treatment of anxiet ...

drug with an at-the-time-unidentified molecular target in the brain. Subsequently, it was determined that fenobam acts as a potent and selective

negative allosteric modulator In pharmacology and biochemistry, allosteric modulators are a group of substances that bind to a receptor to change that receptor's response to stimulus. Some of them, like benzodiazepines, are drugs. The site that an allosteric modulator binds t ...

of the

metabotropic glutamate receptor The metabotropic glutamate receptors, or mGluRs, are a type of glutamate receptor that are active through an indirect metabotropic process. They are members of the group C family of G-protein-coupled receptors, or GPCRs. Like all glutamate re ...

subtype mGluR₅, and it has been used as a

lead compound A lead compound (, i.e. a "leading" compound, not to be confused with various compounds of the metallic element lead) in drug discovery is a chemical compound that has pharmacology, pharmacological or biological activity likely to be therapeutical ...

for the development of a range of newer mGluR₅ antagonists. Fenobam has anxiolytic effects comparable to those of

benzodiazepine Benzodiazepines (BZD, BDZ, BZs), sometimes called "benzos", are a class of depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed to treat conditions such as anxiety disorders, ...

drugs, but was never commercially marketed for the treatment of anxiety due to dose-limiting side effects such as amnesia and psychotomimetic symptoms. Following the discovery of its activity as a potent negative allosteric modulator of mGluR₅, fenobam has been re-investigated for many applications, with its profile of combined antidepressant, anxiolytic, analgesic and anti-addictive effects potentially useful given the common co-morbidity of these symptoms. It has also shown promising initial results in the treatment of

fragile X syndrome Fragile X syndrome (FXS) is a genetic disorder characterized by mild-to-moderate intellectual disability. The average IQ in males with FXS is under 55, while about two thirds of affected females are intellectually disabled. Physical features ma ...

. It was developed by a team at McNeil Laboratories in the 1970s.

Chemistry

Fenobam is known to exist in five crystalline forms, all of them exhibiting a tautomeric structure with the proton attached to the five membered ring nitrogen.

References

{{Metabotropic glutamate receptor modulators Anxiolytics Imidazolines Lactams Ureas Chloroarenes Orphan drugs MGlu5 receptor antagonists Abandoned drugs

Chemistry

See also

References