Sleep laboratory study of the effects of zolpidem in insomniac patients

Abstract

In a multicenter trial in Italian neurologic and psychiatric departments, 1165 patients were given the hypnotic agent zolpidem. Of these, 1152 were evaluable for efficacy (39% men, 61% women; mean age, 51.4 ± 16.4 years; range, 18 to 95 years). The patients' insomnia included all types and either dated from before their admission or was due to their stay in the hospital. After a baseline night with placebo, patients were given zolpidem for at least 7 nights (10 mg for the first 3 nights, with the possibility of subsequently raising it to 20 mg for patients less than 65 years of age). Treatment could be prolonged to 21 nights if necessary. The trial ended with a 3-night placebo withdrawal period. Activity was assessed by daily patient sleep diaries, and by questionnaires and visual analogue scales measuring sleep quality completed by the patients at waking after the baseline placebo night, the first and last nights of obligatory treatment, the last night of optional treatment, and the first and last nights of placebo withdrawal. The mean duration of zolpidem treatment was 11.5 ± 6.7 days. Only 21.5% of the patients required the 20-mg dose after the third night, in line with the severity of insomnia in this population. Zolpidem produced an immediate improvement in all measured sleep parameters, the quality of sleep, and the patients' subjective opinion of their condition on waking (after first day of treatment, P < 0.01 compared with placebo baseline). Observations during the placebo withdrawal period, after the active treatment, confirmed there were no problems in stopping the drug, and in particular, no rebound insomnia was reported. Both doses—10 mg and 20 mg—were well tolerated; only 4.3% of patients reported adverse events attributable to the drug. This trial in 1152 insomniac patients confirms the marked efficacy and safety of zolpidem, an imidazopyridine hypnotic.