The effect of flunitrazepam on acoustic reflex--a methodological pilot study.

Four healthy volunteers took part in this study in four sessions at one week intervals minimum. Three intravenous dose levels of flunitrazepam as well as placebo (saline) were investigated. The sessions were randomized and the study was double blind. The results show that a significant correlation exists between the serum concentrations of flunitrazepam and acoustic reflex amplitude, latency, Maddox wing readings and subjective sedation. Critical flicker fusion frequency test was insensitive in this respect. We conclude that acoustic reflex may be a new method for determination of benzodiazepine effects in man.