Chronoadministration-dependent anxiolytic and hypnotic effects of lormetazepam

The same benzodiazepine can predominantly carry out hypnotic or anxiolytic activities which depend on factors other than dosage. Based on this supposition we evaluated the clinical activity of lormetazepam in relation to different daily administration times. Twelve subjects, affected by sleep disturbances attributable to neurotic anxiety, were divided into two subgroups. For one week, to subgroup A we administered, in the morning, 1 mg of lormetazepam, in the form of drops, and, at night, placebo; in the case of subgroup B, the treatment was reversed. The following week, the treatment sequence was inverted for both groups. The anxiolytic effect was rated on the Hamilton Rating Scale for Anxiety (HRSA), for each administration sequence, before treatment and on the 4th and 7th day after treatment; also, on the 4th and 7th day, a subjective evaluation of sleep was obtained by means of a questionnaire. The reduction in anxiety, more marked on the 7th day, was evidenced with both administration sequences. With regard to the hypnoinducing effect, a significant difference - i.e., shorter sleep latency and longer sleep duration - was observed on the 7th day when lormetazepam was administered at night.