Effects of ramelteon on insomnia symptoms induced by rapid, eastward travel

Objective: Ramelteon, an MT₁/MT₂ melatonin receptor agonist, was evaluated for its ability to reduce sleep-onset difficulties associated with eastward jet travel. Methods: Healthy adults (n= 110) with a history of jet lag sleep disturbances were flown eastward across five time zones from Hawaii to the east coast of the US. Ramelteon 1, 4, or 8. mg or placebo was administered 5. min before bedtime (local time) for four nights. Sleep parameters were measured using polysomnography (PSG) on Nights 2, 3, and 4. Next-day residual effects were assessed using psychomotor and memory function tests. Results: Compared to placebo, there was a significant decrease in mean latency to persistent sleep (LPS) on Nights 2-4 with ramelteon 1. mg (-10.64. min, P= 0.030). No consistent significant differences were observed with ramelteon vs. placebo on measures of next-day residual effects except on Day 4 where participants in all ramelteon groups performed significantly worse on the immediate memory recall test compared with placebo (P≤ 0.05). The incidence of adverse events was similar for ramelteon and placebo. Conclusion: After a 5-h phase advance due to eastward jet travel, ramelteon 1. mg taken before bedtime for four nights reduced mean LPS relative to placebo in healthy adults.