Drug Insight: the use of melatonergic agonists for the treatment of insomnia-focus on ramelteon.
Melatonin, a chronobiotic that participates in the control of the circadian system, is known for its sleep-promoting effects, which include shortening of sleep latency and lengthening of sleep duration. As a result of its short half-life, melatonin does not exhibit undesirable side effects, and its broad applicability for a variety of sleep problems has been the focus of numerous scientific studies. Melatonin has not, however, received regulatory approval from the US FDA as a drug, because it can be sold freely as a food supplement. Consequently, there has been an active search for patentable melatonin receptor ligands in recent years. Ramelteon, an agonist that acts solely on melatonin MT(1) and MT(2) receptors, is of particular interest, and preliminary research indicates that it holds considerable promise for clinical applications. Ramelteon has been shown to induce sleep initiation and maintenance in various animal models and in clinical trials. In chronic insomnia, ramelteon decreases sleep latency and increases total sleep time and sleep efficiency, without causing hangover, addiction or withdrawal effects. Ramelteon is thought to promote sleep by influencing homeostatic sleep signaling mediated by the suprachiasmatic nucleus. Although ramelteon's metabolism and pharmacokinetics differ from those of melatonin, its safety seems to be sufficient for short-term application. Its long-term effects remain to be determined.
Pandi-Perumal
Seithikurippu R
SR
Comprehensive Center for Sleep Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, Mount Sinai School of Medicine, New York, NY 10029, USA. pandiperumal@gmail.com
Srinivasan
Venkataramanujan
V
Poeggeler
Burkhard
B
Hardeland
Rüdiger
R
Cardinali
Daniel P
DP
D000818:Animals; D006801:Humans; D007192:Indenes / Q000627:therapeutic use*; D044094:Receptors, Melatonin / Q000819:agonists* / Q000502:physiology; D007319:Sleep Initiation and Maintenance Disorders / Q000188:drug therapy*
D007192:Indenes; D044094:Receptors, Melatonin; C495910:ramelteon