Effects of indeloxazine hydrochloride on sleep in normal humans

The effects of 40 mg of indeloxazine hydrochloride, a cerebral metabolic enhancer, on sleep were investigated in 6 healthy male students. Polygraphic recordings were made for 8 consecutive nights on each subject. An inert placebo was given on the first 3 nights and on the 7th and 8th nights, and 40 mg of indeloxazine was administered on the 4th, 5th and 6th nights. Drug and placebo were administered orally at 21:30 h, and the recording of polysomnograms started at 22:00 h and ended at 8:00 h the next morning. The polysomnograms were evaluated by computerized automatic analysis using the interval histogram method. Indeloxazine prolonged both sleep latency and REM latency, and increased stage 1 sleep, but decreased stages 3, 4 and REM sleep. A significant increase of REM sleep was observed on the 7th and 8th recovery nights. No obvious changes were shown in the subjective assessments after administration of the drug. These results suggest that the effects of indeloxazine on sleep are similar to those of the tricyclic antidepressants. Furthermore, polysomnographic examinations might be useful in evaluating the pharmacological properties of cerebral metabolic enhancers.