[A comparative study of the development of drug differentiation between mexidol and phenazepam].

Interceptive stimulus properties of mexidol (50 and 100 mg/kg, i.p.) and phenazepam (2 mg/kg, i.p.) were compared using the standard operant model of liquid-reinforced drug discrimination (DD) procedure in male albino rats. Successful DD development has been shown in 100% of phenazepam-pretreated rats, while only 10% of mexidol-treated animals demonstrated DD. In the case of a high stimulus control, both mexidol and phenazepam DD manifestations showed high reproducibility (not less than 80% adequate reactions) and stability. The results suggest that mexidol, while possessing interceptive stimulus properties, belongs to the group of moderately discriminated psychotropic drugs.