ORG50081

ORG50081 is a small molecule psychotropic agent originally developed by Organon (and later Schering-Plough) for the treatment of primary insomnia. It functions primarily as a potent antagonist at the 5-HT2A and 5-HT2C serotonin receptors and the H1 histamine receptor, with additional activity at alpha-1 adrenergic receptors. This pharmacological profile is designed to promote sleep maintenance and onset by blocking wake-promoting signals in the central nervous system. Clinical development reached Phase 2 trials, where its efficacy in improving sleep parameters was evaluated; however, development appears to have been discontinued by Merck & Co. following their acquisition of Schering-Plough in 2009.