A comparison of the efficacy, tolerance and residual effects of zopiclone, flurazepam and placebo in insomniac outpatients.

A double-blind randomized parallel group design was used to compare the tolerance and efficacy of zopiclone 7.5 mg, flurazepam 30 mg and placebo taken each night for 3 weeks in a group of 24 out-patients complaining of sleep disturbance. Analogue rating scales were used to assess the efficacy of the treatments while tolerance and residual effects were measured weekly using a battery of performance tests (Critical Flicker Fusion Threshold, Choice Reaction Time, Letter Cancellation and Digit Span). Physical and clinical examinations, including ECG and EEG, were conducted before and after the experimental period and spontaneously reported side-effects were recorded. Analysis of variance on 24 completed cases (8 patients in each treatment group) showed both active treatments to be significantly better than placebo in shortening sleep onset latency. Flurazepam increased the duration of sleep and produced a "hangover" of impaired psychomotor function. Zopiclone had no observable effect on early morning performance and was free from residual sedative activity. The lack of residual effects with zopiclone 7.5 mg, at a dose shown to be clinically effective, suggests its use in ambulant or out-patient populations where daytime sedation could interfere with every day activities.

Evaluation of cognitive and psychomotor effects of nisoldipine or placebo in healthy volunteers.

The purpose of this study was to compare the cognitive and psychomotor effects of the calcium antagonist nisoldipine with placebo in healthy volunteers over the three-week period of this randomised, double-blind, parallel group trial. Thirty volunteers received either a twice-daily dose of 10 mg nisoldipine or placebo. Psychometric testing and measurement of blood pressure and heart rate were carried out on days 0, 7, 14 and 21. Psychometric testing included: Critical Flicker Fusion (CFF), Choice Reaction Time (CRT), Digit Span (DS), Digit Symbol Substitution Test (DSST), and Letter Cancellation (LC). No significant treatment effects were found. CFF performance improved for both groups during the first week. In the CRT task, significant improvements were observed on days 14 and 21, relative to baseline, for total and motor reaction time. Similar improvements over time were found on the LC and DSST tasks. There were no significant differences between the active treatment and placebo for heart rate and systolic/diastolic blood pressure and nisoldipine was well tolerated. The results of this study indicate that nisoldipine does not have any cognition enhancing properties but, unlike some calcium antagonists, it does not markedly impair CNS activity. Copyright 2000 John Wiley & Sons, Ltd.