Flunitrazepam (Ro 5-4200) and sleep cycle in insomniac patients

The action of flunitrazepam (Ro 5-4200), a benzodiazepine derivative, was assessed on the sleep cycle of insomniac patients by means of all-night reeordings. Baseline placebo nights were compared with the drug (2–8 mg p.o.) and with the placebo post-drug nights.Flunitrazepam induced a shift to faster frequencies of the EEG and a disappearance of sleep stages 3 and 4 while stage 2 was increased. In 10 out of 12 studied insomniacs the compound was effective in inducing and maintaining sleep (decrease in NREM sleep latency, wake time and number of wakes) throughout the drug administration period. Both NREM and REM sleep were increased, the latter most likely in relation to a blockade of processes precluding NREM emergence.The hypnotic action of flunitrazepam was still present during the first withdrawal night, pointing out to a carry over effect.Supported by a grant from Hoffman-La Roche.