Effects of ramelteon on patient-reported sleep latency in older adults with chronic insomnia

Background and purpose: To assess the efficacy and safety of ramelteon, a selective MT₁/MT₂ receptor agonist, for chronic insomnia treatment. Patients and methods: Randomized, double-blind, placebo-controlled 35-night outpatient trial with weekly clinic visits at multiple centers. Patients include older adults (≥65 years; N=829) with chronic insomnia. Placebo, ramelteon 4 mg, or ramelteon 8 mg were taken nightly for five weeks, and patient-reported sleep data were collected using sleep diaries. Primary efficacy was sleep latency at week 1. Sustained efficacy was examined at weeks 3 and 5. Rebound insomnia and withdrawal effects were evaluated during a 7-day placebo run-out. Results: Both doses of ramelteon produced statistically significant reductions in sleep latency vs. placebo at week 1 (ramelteon 4 mg: 70.2 vs. 78.5 min, P=.008; ramelteon 8 mg: 70.2 vs. 78.5 min, P=.008). Patients continued to report reduced sleep latency at week 3 with ramelteon 8 mg (60.3 vs. 69.3 min, P=.003), and at week 5 with ramelteon 4 mg (63.4 vs. 70.6 min, P=.028) and ramelteon 8 mg (57.7 vs. 70.6 min; P<.001). Statistically significant increases in total sleep time were observed with ramelteon 4 mg at week 1 (324.6 vs. 313.9 min, P=.004) and week 3 (336.0 vs. 324.3 min, P=.007) compared with placebo. There was no evidence of significant rebound insomnia or withdrawal effects following treatment discontinuation. The incidence of adverse events was similar among all treatment groups; most were mild or moderate. Conclusions: In older adults with chronic insomnia, ramelteon significantly reduced patient reports of sleep latency over five weeks of treatment with no significant rebound insomnia or withdrawal effects.