Effects of alprazolam on a model of human absences--rhythmic metrazol activity in rats.

Two doses of alprazolam (0.1 and 0.5 mg.kg-1) were tested against a model of human absences--rhythmic EEG activity elicited by low doses of pentylenetetrazol (35 mg.kg-1)--in 10 unrestrained rats with implanted cortical electrodes. Alprazolam delayed the onset of epileptic EEG activity, decreased the number of rhythmic episodes and shortened the total duration of rhythmic activity in a dose-dependent manner. The average duration of episodes of rhythmic activity remained unchanged; other benzodiazepines studied previously were able to influence this measure.