Fenobam has anxiolytic effects comparable to those of benzodiazepine drugs,[1][7][8] but was never commercially marketed for the treatment of anxiety due to dose-limiting side effects such as amnesia and psychotomimetic symptoms.[9][10] 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.[11][12] It has also shown promising initial results in the treatment of fragile X syndrome.[13] It was developed by a team at McNeil Laboratories in the 1970s.[14]
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.
[15]
^Pecknold, JC; McClure, DJ; Appeltauer, L; Wrzesinski, L; Allan, T (1982). "Treatment of anxiety using fenobam (a nonbenzodiazepine) in a double-blind standard (diazepam) placebo-controlled study". Journal of Clinical Psychopharmacology. 2 (2): 129–33. doi:10.1097/00004714-198204000-00010. PMID7042771.
^Palucha, A; Pilc, A (2007). "Metabotropic glutamate receptor ligands as possible anxiolytic and antidepressant drugs". Pharmacology & Therapeutics. 115 (1): 116–47. doi:10.1016/j.pharmthera.2007.04.007. PMID17582504.
^Jacob W, Gravius A, Pietraszek M, Nagel J, Belozertseva I, Shekunova E, Malyshkin A, Greco S, Barberi C, Danysz W (May 2009). "The anxiolytic and analgesic properties of fenobam, a potent mGlu5 receptor antagonist, in relation to the impairment of learning". Neuropharmacology. 57 (2): 97–108. doi:10.1016/j.neuropharm.2009.04.011. PMID19426746. S2CID207224547.
^Carroll, FI (2008). "Antagonists at metabotropic glutamate receptor subtype 5: Structure activity relationships and therapeutic potential for addiction". Annals of the New York Academy of Sciences. 1141: 221–32. doi:10.1196/annals.1441.015. PMID18991960. S2CID45268931.
^Thomas, Sajesh P. (2012). "Polymorphism and tautomeric preference in fenobam and the utility of NLO response to detect polymorphic impurities". Chemical Communications. 48 (85): 10559–10561. doi:10.1039/C2CC34912D. PMID23000909.