Effects of fentanyl and low doses of alcohol on neuropsychological performance in healthy subjects.

The effects of the opioid fentanyl and low doses of alcohol on neuropsychological functions in healthy volunteers were measured. Twenty-four healthy male volunteers participated in this study. Two randomised placebo-controlled cross-over trials were conducted. In group 1, 6 subjects received fentanyl (0.2 microgram/kg body weight) in the order of fentanyl/placebo and 6 subjects in the order of placebo/fentanyl. Group 2 received alcohol in a similar procedure by continuous intravenous infusion, leading to a blood alcohol concentration (BAC) of 0.03%. Impairment was measured via different neuropsychological tests. The results indicate that fentanyl in concentrations commonly used in out-patient surgical procedures produces pronounced cognitive impairment (auditory reaction time, signal detection, sustained attention, recognition) in comparison to placebo. After application of low doses of alcohol (BAC 0.03%) only visual reaction time was impaired in comparison to placebo.