Further assessment of benzodiazepine-tricyclic antidepressant interaction. Effectiveness of combined treatment with ketazolam-nortriptyline on conflict behaviour in rats.

Using Geller and Seifter's conflict behaviour test, ketazolam in rat increases the rate of responses emitted both with and without punishment. Nortriptyline decrease the non-punished component of the schedule without influencing the punished one. With combined treatment, nortriptyline does not modify the effects of ketazolam on punished responses while nortriptyline, 1 h after administration, decreases, though not significantly, the facilitating action of ketazolam. After 24 h it significantly increases the depressant action of this benzodiazepine. The results suggest that with the combination tricyclic anti-depressant-benzodiazepine, as with these two categories of drugs, there is not always an increase in disinhibiting action, while depressant action has characteristics closely dependent on the properties of the benzodiazepine used.