Psychomotor performance after intake of zopiclone compared with intake of ethanol: a randomized, controlled, double-blinded trial.

The sleep medicine zopiclone (eszopiclone) is commonly used in most Western countries. The focus on legislation for possible traffic-impairing nonalcohol drugs have caused a need for comparing traffic relevant behavior after intake of commonly used psychoactive drugs to blood alcohol concentrations (BACs). We aimed to compare psychomotor effects at 3 levels of behavior at different blood zopiclone concentrations to effects seen at different BACs. We performed a randomized double-blinded trial on 16 healthy volunteers who received either 10 or 5 mg zopiclone, 50 g ethanol or placebo in a crossover design. The volunteers performed computerized tests at baseline, 1, 3.5, and 6.5 hours after intake, accompanied by blood sampling. Impairment was found at all 3 behavior levels. For zopiclone, impairment was most pronounced at behavior level 1 (automotive behavior); a mean blood zopiclone concentration at 39 μg/L achieved 1 hour after intake of 10 mg zopiclone was accompanied by more impairment than BAC 0.074 %. At behavior levels 2 (control behavior) and 3 (executive planning), the psychomotor impairment accompanying approximately 39 μg/L zopiclone seemed comparable to a BAC of approximately 0.074%. No test components were impaired at 6.5 hours after intake.