Single daily dose treatment of anxiety with clobazam or dipotassium clorazepate.

1 Forty-four clinically anxious patients entered a comparative double-blind trial of clobazam 20 mg, clobazam 30 mg and dipotassium clorazepate 15 mg, all drugs given as a single dose at night. 2 Assessment by the Hamilton Anxiety Scale, Morbid Anxiety Inventory (Salkind) and a Visual Analogue Scale showed a statistically significant improvement for all treatment groups after 2 weeks, with continued improvement after a further 2 weeks. 3 Daytime drowsiness was the commonest side-effect in all treatment groups but there was a tendency for a lower incidence in patients on clobazam. There was no evidence of a dose-related incidence of drowsiness in the clobazam 20 mg and 30 mg groups. Other side-effects were few and nonspecific. 4 Clobazam is a 1,5-benzodiazepine with an elimination half-life of 18 hours. When given in single doses of 20-30 mg at night it has an equivalent effect to dipotassium clorazepate 15 mg.