Ramelteon

Ramelteon is a potent, highly selective, and orally active agonist of MT1/MT2 with Ki values of 14 and 112 pM, respectively. Ramelteon has the potential for the research of insomnia. Ramelteon consistently reduces sleep onset after long-term treatment, with no next-morning residual effects or rebound insomnia or withdrawal symptoms upon discontinuation^[1][2]. IC50 & Target:MT1, MT2^[1] In Vivo: Ramelteon (p.o.; 0.1 and 1 mg/kg) accelerates reentrainment of running wheel activity rhythm to the new lightdark cycle^[3].
Ramelteon (p.o.; 3, 10, and 30 mg/kg) does not affect learning or memory in rats tested by the water maze task and the delayed match to position task, implying that MT1/MT2 receptor agonists have no abuse potential^[3].
Ramelteon (0.0001, 0.001, 0.01, and 0.1 mg/kg; p.o.; 8 hours) significantly decreases wakefulness at doses of 0.001, 0.01, and 0.1 mg/kg, increases slow-wave sleep at doses of 0.001, 0.01, and 0.1 mg/kg, and increases rapid eye movement sleep at a dose of 0.1 mg/kg^[4].