Effects of zolpidem and flunitrazepam on nocturnal sleep of women subjectively complaining of insomnia

Abstract

Eighteen non-pregnant woman complaining about insomnia were polysomnographically investigated for 3 nights with weekly intervals. They received placebo, 2 mg flunitrazepam or 10 mg zolpidem according to a cross-over double blind design. The patients were selected by general practitioners on the basis of subjective complaints. Zolpidem is a recently introduced short-acting imidazopyridine hypnotic, binding to a subunit of the benzodiazepine 1 receptor. Flunitrazepam is a well-known hypnotic, binding to both the benzodiazepine 1 and 2 receptor subtypes. Objective recording did not substantiate the subjective complaint of insomnia. Sleep patterns during placebo differed only little from that expected from age matched healthy persons. Both flunitrazepam and zolpidem significantly shortened sleep onset (5 min of continuous sleep beginning with NREM 1 sleep). The sleep composition following flunitrazepam was characterized by an increase in NREM 2, a prolongation of the time of REM sleep, a reduction of REM sleep and an increase in NREM 3-4 sleep during the first 2 h of sleep. The sleep composition following zolpidem resembled more than seen in persons without sleep complaints. However, as compared to placebo, there was a decrease of the time spent awake during sleep and an increase in NREM 3-4 during the first 2 of sleep.