[Pharmacologic effects of tofizopam (Grandaxin)].

A great number of the anxiolytics used in the clinical practice are structurally 1,4-benzodiazepines. Tofisopam is the first derivative which differs from the so-called classical benzodiazepines in the position of the nitrogen atoms i.e. in the case of tofisopam they are vicinals (2.3-). This difference in its structure is suspected to be responsible for the different pharmacological and clinical profile of tofisopam. In addition to the anxiolytic activity, sedative, muscle relaxant and anticonvulsive effects are the main characteristics of the most frequently used representative of 1,4-benzodiazepines, diazepam. In contrast, to the above mentioned, tofisopam produces sedation only in higher doses, and does not possess anticonvulsive and appreciable muscle relaxant effects. Tofisopam does not induce sleep even in subtoxic doses, and only high doses enhance the effect of barbiturates and ethanol. Applying doses above 200 mg/kg, tofisopam exhibits effects similar to that of neuroleptics (e.g. catalepsy, ptosis, decrease of pentetrazol threshold, potentiation of amphetamine and apomorphine stereotypy). After repeated administration tolerance to the drug was not observed. Tofisopam does not bind in the CNS neither to the 1,4-benzodiazepine, nor to the GABA receptors, but it enhances the binding of benzodiazepines and muscimol to their binding sites. Tofisopam has also mixed dopamine agonist and antagonist like properties.