Driving performance in the morning after bedtime vornorexant administration: A randomized clinical trial using a...

Sedative hypnotics can impair driving performance to a degree comparable to blood alcohol concentrations of 0.05%-0.08%. This study aimed to evaluate the residual effect of vornorexant, a novel orexin receptor antagonist, on next morning driving performance relative to a predefined clinically meaningful threshold.

Participants received 10 and 20 mg of vornorexant and placebo for eight consecutive nights and zopiclone on Days 1 and 8 in a four-way crossover and double-blind manner. Driving performance at 9-h post-dose was assessed measuring the standard deviation of the lateral position (SDLP) on Days 2 and 9 (days after single and repeated administration) using a validated driving simulator. Pharmacokinetics were also evaluated.

Sixty-one participants were randomized and 55 completed the study. The mean of drug-placebo changes in SDLP (ΔSDLP) following vornorexant 10 and 20 mg were 0.767 and 2.132 cm on Day 2, and -0.422 and -0.040 cm on Day 9, respectively, whereas approximately 6 cm in zopiclone. All the upper bounds of the 90% confidence intervals of these changes were below the predefined clinically significant threshold. Symmetry analysis found no differences in the proportion of participants with ΔSDLP exceeding the threshold in either impairing or improving from 0 cm, at vornorexant 10 mg on Days 2 and 9 and 20 mg on Day 9. Pharmacokinetic analysis showed consistent plasma concentrations of vornorexant in single and repeated dosing.

Single and repeated administration of 10 and 20 mg vornorexant induced no clinically meaningful impairment in driving performance in healthy Japanese participants.