Chronic effects of flunitrazepam on shock-induced behavioral inhibition in adult male rats.

Flunitrazepam has been reported to trigger cases of extreme violence in man and recently it was shown to heighten aggression in experimental rats. The underlying mechanisms may involve disinhibited/impulsive behavior. Here, tolerance developed to the behavioral disinhibiting effect of flunitrazepam in Vogel's drinking conflict model, both in rats treated with flunitrazepam (0.32 mg/kg/day) for three weeks, as well as in rats treated for six weeks (0.32 mg/kg/day three weeks + 0.56 mg/kg/day three weeks). The results suggest that behavioral disinhibition is of limited importance in the mechanisms underlying the pro-aggressive effect of chronic flunitrazepam administration.