Clobazam exerts an anticonvulsant action in immature rats.

The anticonvulsant action of 1,5-benzodiazepine clobazam was studied in 12-, 18-, and 25-day-old rats. Cortical epileptic afterdischarges (ADs) elicited by rhythmic electrical stimulation of the sensorimotor cortical area were used as a model in animals with implanted electrodes. As far as the duration of ADs is concerned, clobazam in doses of 1 or 5 mg/kg i.p. blocked the progressive increase with repeated stimulations in all age groups and the higher dose significantly shortened ADs in 25-day-old rats. The intensity of movements accompanying stimulation was decreased only by the 5 mg/kg dose in 25-day-old animals, whereas clonic seizures were less intense after both doses in 12- and 25-day-old rat pups. Clobazam exerted an anticonvulsant action at all the developmental stages studied; the lower efficacy in 18-day-old rats (described also for clonazepam) remains to be analyzed.