piperidines and suvorexant

Insomnia and hypersomnia are conditions with multifactorial causes that can be difficult to treat. There have been recent developments and changes in the treatment of both conditions, including the addition of some agents that have a novel mechanism of action. This review summarizes recent changes and highlights pertinent updates.. Benzodiazepine receptor agonists received a warning in 2019 regarding the possibility of complex sleep behaviors, such as sleepwalking. Zolpidem has been marketed in new dosage forms that include sublingual tablets and oral spray formulations. Orexin receptor antagonists appear to be well tolerated with a good safety profile. Suvorexant received an approval for the treatment of patients with comorbid insomnia and dementia. Lemborexant was demonstrated to be effective for maintenance insomnia. Trazodone was shown to affect the oligomerization of tau proteins thus suggesting potential implications in attenuating dementia pathology. Pitolisant, a novel histamine-3 receptor antagonist/inverse agonist, gained approval for the treatment of excessive daytime sleepiness in adults with narcolepsy as well as obstructive sleep apnea. Solriamfetol, a new norepinephrine and dopamine reuptake inhibitor, was approved for hypersomnolence based on good efficacy, but with cardiovascular warnings.. Recent advancements in the treatment of insomnia includes agents with novel mechanisms, new indications, and new dosage forms. Risk of complex sleep behaviors, and possible next-day driving impairment, should be discussed for all agents used for insomnia, including orexin receptor antagonists. Novel agents also are available for hypersomnia and there are options beyond traditional stimulants that may have great utility.

Topics: Azepines; Carbamates; Dementia; Disorders of Excessive Somnolence; GABA-A Receptor Agonists; Humans; Orexin Receptor Antagonists; Phenylalanine; Piperidines; Pyridines; Pyrimidines; Sleep Aids, Pharmaceutical; Sleep Apnea, Obstructive; Sleep Initiation and Maintenance Disorders; Trazodone; Triazoles; Zolpidem

The importance of methyl groups in modulating biological activity, selectivity, solubility, metabolism and pharmacokinetic/pharmacodynamic properties of biologically active molecules is highlighted. The information compiled from selected beneficial cases, focuses mostly on marketed drugs and clinical candidates, and indicates that the methylation strategy has been successful in drug design.

Topics: Animals; Azepines; Dogs; Drug Design; Humans; Methylation; Molecular Structure; Pharmaceutical Preparations; Pharmacokinetics; Pharmacology; Piperidines; Pyrimidines; Rats; Solubility; Triazoles

Insomnia is a serious medical and social problem, its prevalence in the general population ranges from 9 to 35% depending on the country and assessment method. Often, patients are subject to inappropriate and therefore dangerous pharmacotherapies that include prolonged administration of hypnotic drugs, benzodiazepines and other GABAA receptor modulators. This usually does not lead to a satisfactory improvement in patients' clinical states and may cause lifelong drug dependence. Brain state transitions require the coordinated activity of numerous neuronal pathways and brain structures. It is thought that orexin-expressing neurons play a crucial role in this process. Due to their interaction with the sleep-wake-regulating neuronal population, they can activate vigilance-promoting regions and prevent unwanted sleep intrusions. Understanding the multiple orexin modulatory effects is crucial in the context of pathogenesis of insomnia and should lead to the development of novel treatments. An important step in this process was the synthesis of dual antagonists of orexin receptors. Crucially, these drugs, as opposed to benzodiazepines, do not change the sleep architecture and have limited side-effects. This new pharmacological approach might be the most appropriate to treat insomnia.

Topics: Acetamides; Animals; Azepines; Benzofurans; Humans; Isoquinolines; Models, Biological; Orexin Receptor Antagonists; Orexin Receptors; Piperidines; Pyrimidines; Sleep; Sleep Initiation and Maintenance Disorders; Thiazoles; Triazoles; Wakefulness

Orexins A and B (hypocretins 1 and 2) and their two receptors (OX1R and OX2R) were discovered in 1998 by two different groups. Orexin A and B are derived from the differential processing of a common precursor, the prepro-orexin peptide. The neuropeptides are expressed in a few thousand cells located in the lateral hypothalamus (LH), but their projections and receptor distribution are widespread throughout the brain. Remarkably, prepro peptide and double (OX1R/OX2R) receptor knock out (KO) mice reproduce a sleep phenotype known in humans and dogs as narcolepsy/cataplexy. In humans, this disease is characterized by the absence of orexin producing cells in the LH, and severely depleted levels of orexin the cerebrospinal fluid. Null mutation of the individual OX1R or OX2R in mice substantially ameliorates the narcolepsy/cataplexy phenotype compared to the OX1R/OX2R KO, and highlights specific roles of the individual receptors in sleep architecture, the OX1R KO demonstrating an a attenuated sleep phenotype relative to the OX2R KO. It has therefore been suggested that orexin is a master regulator of the sleep-wake cycle, with high activity of the LH orexin cells during wake and almost none during sleep. Less than 10years later, the first orexin antagonist, almorexant, a dual orexin receptor antagonist (DORA), was reported to be effective in inducing sleep in volunteers and insomnia patients. Although development was stopped for almorexant and for Glaxo's DORA SB-649868, no less than 4 orexin receptor antagonists have reached phase II for insomnia, including Filorexant (MK-6096) and Suvorexant (MK-4305) from Merck. Suvorexant has since progressed to Phase III and dossier submission to the FDA. These four compounds are reported as DORAs, however, they equilibrate very slowly at one and/or the other orexin receptor, and thus at equilibrium may show more or less selectivity for OX1R or OX2R. The appropriate balance of antagonism of the two receptors for sleep is a point of debate, although in rodent models OX2R antagonism alone appears sufficient to induce sleep, whereas OX1R antagonism is largely devoid of this effect. Orexin is involved in a number of other functions including reward and feeding, where OX1R (possibly OX2R) antagonists display anti-addictive properties in rodent models of alcohol, smoking, and drug self-administration. However, despite early findings in feeding and appetite control, orexin receptor antagonists have not produced the anticipated eff

Topics: Acetamides; Animals; Azepines; Behavior, Addictive; Benzofurans; Feeding Behavior; Humans; Intracellular Signaling Peptides and Proteins; Isoquinolines; Mice; Neuropeptides; Orexin Receptor Antagonists; Orexin Receptors; Orexins; Piperidines; Pyrimidines; Rats; Reward; Sleep; Sleep Initiation and Maintenance Disorders; Thiazoles; Triazoles

Topics: Animals; Arousal; Azabicyclo Compounds; Azepines; Benzodiazepines; Cognitive Behavioral Therapy; Doxepin; Dreams; Histamine Agonists; Histamine Antagonists; Humans; Hypnotics and Sedatives; Hypothalamus; Orexin Receptors; Piperazines; Piperidines; Receptors, G-Protein-Coupled; Receptors, GABA; Receptors, Histamine H3; Receptors, Neuropeptide; Sleep Initiation and Maintenance Disorders; Triazoles