Next-day effects of ramelteon (8 mg), zopiclone (7.5 mg), and placebo on highway driving performance, memory functioning, psychomotor performance, and mood in healthy adult subjects.

STUDY OBJECTIVES: To evaluate the next-morning residual effects of ramelteon (8 mg), zopiclone (7.5 mg), and placebo on driving performance, memory functioning, psychomotor performance, and mood in healthy adult subjects following bedtime dosing and a middle of the night awakening. DESIGN: Single-center, randomized, double-blind, double-dummy, placebo-controlled, crossover study. SETTING: Utrecht University, The Netherlands. PARTICIPANTS: 30 healthy volunteers (15 males and 15 females). INTERVENTIONS: a single dose of ramelteon (8 mg), zopiclone (7.5 mg), and placebo, administered at bedtime. MEASUREMENTS: A balance test was performed at night. Other tests were performed the following morning, 8.5 h after administration. Subjects performed a 100-km highway driving test in normal traffic. Primary outcome measure was the standard deviation of the lateral position (SDLP), i.e., the weaving of the car. After driving, cognitive, memory, and psychomotor tests were performed and mood was assessed. RESULTS: SDLP was significantly increased after the intake of ramelteon (+2.2 cm) and zopiclone (+2.9 cm). Ramelteon and zopiclone produced significant impairment on reaction time (P