Effects of zopiclone, flunitrazepam, triazolam and levomepromazine on the transient change in sleep-wake schedule: polygraphic study, and the evaluation of sleep and daytime condition.

1. The effects of zopiclone 10mg (ZP), flunitrazepam 1mg (FN), triazolam 0.25mg (TZ) and levomepromazine 5mg (LP) on two models of sleep-wake schedule change-6 hours advanced shift: (A-shift), and 6 hours delayed: (D-shift)--were investigated in 6 healthy volunteers using polysomnography. 2. In A-shift with placebo, TST, SEI, %SR and REM/NREM decreased. ZP, FN and TZ shortened SL. All drugs increased TST and SEI. TZ and LP increased %SR and REM/NREM. 3. In D-shift with placebo, TST decreased, SWSL was prolonged, %S3+4 decreased, and %SR and REM/NREM increased. All drugs increased TST. ZP and LP shortened SWSL. All drugs increased %SWS. ZP, FN and TZ decreased %SR. ZP and FN decreased REM/NREM. 4. Daytime mental and physical conditions were worse than usual on more than half of the days in A- and D-shift. LP and FN caused some inadequate conditions on the following days. Significantly higher REM/NREM was observed in the nights before the days with worse mental conditions in D-shift, and lower REM/NREM in the nights before the days with worse physical conditions in A-shift. 5. It is concluded that TZ and ZP are superior to the others for A-shift and D-shift, respectively.