Sublingual zolpidem in early onset of sleep compared to oral zolpidem: polysomnographic study in patients with primary insomnia

Objective: To compare the hypnotic effects of a single dose of a sublingual formulation of zolpidem (Edluar*) 10 mg vs oral formulation (Ambien dagger) 10 mg by polysomnography (PSG) in DSM-IV primary insomnia patients. Primary objective was to compare the two formulations on sleep induction, measured by latency to persistent sleep (LPS), sleep onset latency (SOL) and latency to stage 1 (ST1L). Research and methods: This was a randomized, double-blind, two-period, cross-over multi-centre study in which each period comprised two successive PSG recording nights. Treatment was administered when PSG recordings started. Subjective sleep and residual effects were assessed the next morning. Results: Seventy female and male patients aged 19-64 were analysed. Sublingual zolpidem significantly shortened LPS by 34% or 10.3 minutes as compared to oral zolpidem (95% CI: -4.3 min to -16.2 min, p=0.001). SOL and ST1L were also significantly shortened (p<0.01). Furthermore the two formulations were comparable in terms of sleep maintenance properties based on total sleep time (TST). The improvement in subjective sleep and next-day residual effects did not differ between the two treatments. Both routes of administration were well tolerated. Conclusions: The results demonstrate that sublingual zolpidem is superior to an equivalent dose of oral zolpidem in terms of sleep inducing properties in a carefully selected sample of primary insomnia patients.