Efficacy and Safety of Ramelteon in Subjects With Mild to Moderate Alzheimer's Disease

Epidemiological data for 2005 show that an estimated 4.2 million people in the US suffer from Alzheimer's disease, often necessitating caregiver assistance, which can in many cases progress to institutionalization. Subjects with Alzheimer's disease dementia frequently experience disturbed sleep patterns characterized by insufficient nocturnal sleep and excessive daytime napping, which has been associated with both cognitive and behavioral pathology such as impaired daytime functioning, agitation, and nocturnal wandering. Although the causality of sleep disturbances in Alzheimer's disease remains unclear; some research suggests that the fragmented sleep and associated behavioral disturbances could be related to the degeneration of the serotonergic and noradrenergic innervation of suprachiasmatic nucleus andsubsequent disruption in melatonin secretion patterns. Additionally, research suggests that melatonin levels are decreased in patients with Alzheimer's disease In the United States, ramelteon is marketed for the treatment of insomnia characterized by difficulty with sleep onset and is under global development for the treatment of transient, chronic insomnia and circadian rhythm sleep disorders. It is believed that ramelteon works by binding melatonin to MT1/MT2 receptors in the suprachiasmatic nucleus which inhibits firing of specific neurons, which is thought to attenuate the alerting signal and allows the homeostatic mechanism to express itself and promote sleep. Study participation is anticipated to be about 11 weeks (approximately 3 months).