A retrospective study of the efficacy of ramelteon for insomnia: relevance of dose and timing of administration

The objective of the study was to investigate the efficacy of ramelteon for insomnia, particularly with circadian disturbance, focusing on the relevance of dose and timing of administration. We reviewed the chart data of 145 continuous patients who received ramelteon for insomnia for the first time at the sleep clinic of the Department of Psychiatry, Fujita Health University Hospital (Aichi, Japan) between October 2010 and May 2014. Treatment efficacy was assessed using the Clinical Global Impression of Improvement (CGI-I) scale and this relationship with the dose and timing of administration was further analyzed. Symptoms in 56.6% of patients were improved (CGI-I ≦ 3). In a subgroup of 114 patients, especially aiming for phase advance, the ratio of improvement was 64.0%. The ratio of patients reporting symptom improvement tended to be great in the low-dose (1 or 2 mg) group and the low-dose + early administration (> 5 h before habitual bedtime) group, as compared with the remaining group; however, this difference was not statistically significant. Significantly fewer cases in the low-dose group reported carry-over effects. In our specialized sleep clinic, there were many refractory cases of insomnia; however, ramelteon was effective in about half of such patients. Particularly, ramelteon tended to be more effective for patients with insomnia and circadian disturbances, although differences among groups were not statistically significant. The effectiveness of the low-dose administration or the combination of low-dose and early-administration was equal or slightly better and acceptability tended to be better than other modes of administration.