The effects of ramelteon in a first-night model of transient insomnia.

Objective: To evaluate the efficacy and safety of ramelteon, a highly selective MT(1)/MT(2) melatonin receptor agonist, for the treatment of transient insomnia in adults.

Methods: In a randomized, double-blind, placebo-controlled, multi-center study, 289 adults naive to a sleep laboratory environment were randomized to receive a single nighttime dose of ramelteon 8 mg, 16 mg, or placebo. The primary variable was latency to persistent sleep measured by polysomnography. Additional objective and subjective sleep parameters as well as next-morning residual effects were assessed.

Results: Ramelteon 8 mg treatment significantly reduced latency to persistent sleep compared with placebo (12.2 min vs. 19.7 min, P=0.004). Total sleep time was significantly increased with both ramelteon 8 mg (436.8 min, P=0.009) and ramelteon 16 mg (433.1 min, P=0.043) compared with placebo (419.7 min). Ramelteon did not alter sleep architecture, and no significant next-morning residual effects were detected. The incidence of adverse events was similar for the ramelteon and placebo groups and most were considered mild or moderate.

Conclusion: Ramelteon 8 mg significantly decreased latency to persistent sleep and increased total sleep time, with no significant next-morning psychomotor, memory, or cognitive effects in this first-night model of transient insomnia.