1 Clobazam is a 1,5-benzodiazepine the pharmacological profile of which differs from that of the 1,4 benzodiazepines in that it displays a wide separation of psychosedative or 'tranquillizing' properties from impairment of motor coordination. This is associated with a relative lack of muscle relaxant activity. 2 In man it seems to be an effective anxiolytic agent when given in daily doses of 20-30 mg but produces minimal effects on psychomotor performance at these dose levels. 3 Clobazam has a long elimination half-life of about 18 h; the main metabolite is N-desmethylclobazam. Clobazam seems to share the good safety and tolerability characteristics of the 1,4 benzodiazepines.