Biperiden administration during REM sleep deprivation diminished the frequency of REM sleep attempts

Sixteen subjects were assigned to a group using either placebo or biperiden, with eight subjects in each group. Both groups were studied for one acclimatization night, one baseline night, four nights of rapid eye movement (REM) sleep deprivation and two recovery nights. All the subjects received either placebo or 4 mg biperiden 1 hour before sleep during the four nights of REM sleep deprivation. During the baseline and the recovery nights both groups received placebo capsules. The results showed that REM sleep time during the REM sleep deprivation was reduced by 70-75% below the baseline night in both groups. The number of attempts to enter REM sleep was significantly reduced by biperiden as compared to placebo for each of the four REM sleep deprivation nights. Because the total sleep time in the biperiden group was reduced, the number of REM sleep attempts was corrected by the total sleep time. The adjusted number of REM sleep attempts was also significantly reduced in the biperiden group. REM sleep latency showed a reduction in the placebo group, whereas in the biperiden group REM sleep latency was unchanged throughout the deprivation nights. In the recovery night REM sleep time was increased in both groups, with no differences between the groups. The REM sleep latency showed a reduction in the first recovery night in both groups that persisted through the second recovery night. The above findings support the role of biperiden as a REM sleep suppressive drug.