Ramelteon is a tricyclic synthetic analog of
melatonin that acts specifically on MT1 and MT2
melatonin receptors.
Ramelteon is the first
melatonin receptor agonist approved by the Food and Drug Administration (FDA) for the treatment of
insomnia characterized by sleep onset difficulties.
Ramelteon is both a chronobiotic and a
hypnotic that has been shown to promote sleep initiation and maintenance in various preclinical and in clinical trials. The efficacy and safety of
ramelteon in patients with
chronic insomnia was initially confirmed in short-term placebo-controlled trials. These showed little evidence of next-day residual effects,
withdrawal symptoms or
rebound insomnia. Other studies indicated that
ramelteon lacked abuse potential and had a minimal risk of producing dependence or adverse effects on cognitive or psychomotor performance. A 6-month placebo-controlled international study and a 1-year open-label study in the USA demonstrated that
ramelteon was effective and well tolerated. Other potential
off-label uses of
ramelteon include
circadian rhythm sleep disorders such as shift-work and
jet lag. At the present time the
drug should be cautiously prescribed for short-term treatment only.