Tofisopam (marketed under brand names Emandaxin and Grandaxin) is a 2,3-benzodiazepine drug which is a benzodiazepine derivative. In contrast to classical 1,4-benzodiazepines, the compound does not bind to the benzodiazepine binding site of the gamma-aminobutyric acid receptor and its psychopharmacological profile differs from such compounds. Although Tofisopam is not approved for sale in North America, it is approved for use in various countries worldwide, including parts of Europe. The D-enantiomer (dextofisopam) is currently in phase II trials in the U.S. for the treatment of irritable bowel syndrome. |
Brands | Emandaxin Grandaxin Seriel
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Categories | Benzodiazepines
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Synonyms | Tofizopam
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indication
For the treatment of anxiety and alcohol withdrawal.
pharmacology
Like other benzodiazepines, tofisopam possesses anxiolytic properties but unlike other benzodiazepines it does not have anticonvulsant, sedative, skeletal muscle relaxant, motor skill-impairing or amnestic properties. While it may not be an anticonvulsant in and of itself, it has been shown to enhance the anticonvulsant action of classical 1,4-benzodiazepines such as diazepam (but not sodium valproate, carbamazepine, phenobarbital, or phenytoin).
mechanism of action
Tofisopam does not bind to the benzodiazepine binding site of the gamma-aminobutyric acid receptor. One study (Rundfeldt C. et al.) has shown that tofisopam acts as an isoenzyme-selective inhibitor of phosphodiesterases (PDEs) with highest affinity to PDE-4A1 (0.42 μM) followed by PDE-10A1 (0.92 μM), PDE-3 (1.98 μM) and PDE-2A3 (2.11 μM).
toxicity
The onset of impairment of consciousness is relatively rapid in benzodiazepine poisoning. Onset is more rapid following larger doses and with agents of shorter duration of action. The most common and initial symptom is somnolence. This may progress to coma (Grade I or Grade II) following very large ingestions. Oral, rat LD50 is 825 mg/kg.
biotransformation
Hepatic.
half life
6-8 hours