Effects of Neurotropin on polysomnographic patterns in normal humans

The effects of Neurotropin, an analgesic drug, on polysomnographic patterns were investigated in 6 male healthy volunteers aged from 18 to 23 years (mean age 21.1 years). Polysomnographic recordings were made for 6 consecutive nights from each subject. An inert placebo, identical to the Neurotropin tablets, was given on the first 3 nights and on the sixth night. Forty-eight mg of Neurotropin (4 tablets containing 12 mg of Neurotropin each) was administered on the fourth and fifth nights. The drug and placebo were administered orally 30 min before starting the record of polysomnograms, i.e. around 22.00 h and continued until the natural awakening of the subjects the next morning. The polysomnographic record of the first night was discarded from the data, because of the first night effect. Neurotropin, given on the fourth night, significantly reduced total sleep time, stage 3 and percent of stage 3 as compared to those of the baseline placebo nights. Neurotropin given on the fifth night significantly decreased only total awakening time. These effects were not observed on the sixth placebo night (recovery night). As for the subjective assessments, no obvious changes were observed after administration of the drug. These results suggest that Neurotropin decreases total sleep time as well as stage 3 sleep. However, these effects are transient and unaccompanied by rebound phenomena. It is further suggested that Neurotropin seems to elevate slightly and transiently the arousal level.