Effects of Diazepam and Nitrazepam on Psychophysiological Functions in Normal Humans

The infuluence of dizepam and nitrazepam on arousal level, muscle strength, psychomotor performance and memory function using the photopalpebral reflex (PPR), critical flicker frequency (CFF), tapping test, (CRT) and mamory drum test (MDT) were investigated in the present study. The healtyv male universitv atudents were given diazepam 5 mg and 10 mg, and plecedo in a doubleblind, cross-over design. The tests and subjective assessments were performed before and after drug administration. All drugs produced a prolongation of PPR latencies and a decrease of CFF, and diazepam 10 mg and nitrazepam 10 mg were the most efficacious in producing these phenomena. Tapping rate increased after administration of all agents, and then decreased to control levels. PRT and CRT improved after all drugs and performance on these tasks was most improved by diazepam 10 mg. Memory tasks were impaired following administration of all drugs. No significant changes were observed in the assessments of the subjects. These results suggest that the physiological and psychological tests employed in this study are useful tools for assessing the residual effects of benzodiazepines in normal humans, and that small doses of benzodiazepines lower arousal level, impair memory, but improve motor and psychomotor performance.

Residual effects

Diazepam

Nitrazepam

Psychophysiological tools

Normal humans