The abuse potential of lemborexant, a dual orexin receptor antagonist, according to the 8 factors of the Controlled Substances Act

Fatal acute lemborexant Poisoning: An autopsy case report

A 50-year-old male was found dead in a park. Postmortem analysis using liquid chromatography-tandem mass spectrometry revealed lemborexant concentrations of 1.651 μg/mL in blood from the right heart, 0.236 μg/mL in the urine, and 58.642 μg/mL in the stomach contents. Based on the autopsy findings and postmortem analyses, the cause of death was identified as acute lemborexant poisoning due to an overdose. Although lemborexant is generally considered safe, its excessive ingestion can be fatal. Since no lethal concentration of lemborexant has been reported, the blood levels in this case can serve as a reference. Despite its widespread clinical use, lemborexant is not detected by the rapid urine drug screening tests currently available in Japanese investigative agencies. Forensic pathologists must be vigilant in order not to overlook acute lemborexant poisoning.

Treatment of insomnia associated with alcohol and opioid use: a narrative review

Substance use disorders (SUDs) are associated with profound sleep disturbances, including insomnia, sleep fragmentation, and circadian rhythm dysfunction resulting in serious mental and physical consequences. This minireview presents an overview of the neurocircuitry underlying sleep disturbances in SUDs and elaborates on treatment options with emphasis on alcohol use disorder (AUD) and opioid use disorder (OUD). A PubMed, Embase, CINAHL Plus, Cochrane, and Scopus search were conducted using sleep- and AUD/OUD related keywords from January 1st, 2000, to January 31st, 2023, with preferences for recent publications and randomized-controlled trials. A bidirectional relationship exists between insomnia and addiction with the status of each condition impacting the other in dictating clinical outcome. Existing evidence points to a resurgence of insomnia during detoxification, and unless treated satisfactorily, insomnia may lead to relapse. The discussion summarizes the strengths and limitations of cognitive behavioral therapy and pharmacological treatment for insomnia in SUDs covering evidence from both animal and clinical studies. The assumption of reestablishing normal sleep patterns by attaining and maintaining sobriety is misguided. Comorbid insomnia in patients with SUDs should be approached as an independent condition that requires its own treatment. Future clinical trials are needed with the aim of providing a resource for guiding clinical management of the many patients with insomnia and SUD.

Orexin-mediated motivated arousal and reward seeking

The neuromodulator orexin has been identified as a key factor for motivated arousal including recent evidence that sleep deprivation-induced enhancement of reward behavior is modulated by orexin. While orexin is not necessary for either reward or arousal behavior, orexin neurons' broad projections, ability to sense the internal state of the animal, and high plasticity of signaling in response to natural rewards and drugs of abuse may underlie heightened drug seeking, particularly in a subset of highly motivated reward seekers. As such, orexin receptor antagonists have gained deserved attention for putative use in addiction treatments. Ongoing and future clinical trials are expected to identify individuals most likely to benefit from orexin receptor antagonist treatment to promote abstinence, such as those with concurrent sleep disorders or high craving, while attention to methodological considerations will aid interpretation of the numerous preclinical studies investigating disparate aspects of the role of orexin in reward and arousal.

Orexin Receptor Antagonism: Normalizing Sleep Architecture in Old Age and Disease

Sleep is essential for human well-being, yet the quality and quantity of sleep reduce as age advances. Older persons (>65 years old) are more at risk of disorders accompanied and/or exacerbated by poor sleep. Furthermore, evidence supports a bidirectional relationship between disrupted sleep and Alzheimer's disease (AD) or related dementias. Orexin/hypocretin neuropeptides stabilize wakefulness, and several orexin receptor antagonists (ORAs) are approved for the treatment of insomnia in adults. Dysregulation of the orexin system occurs in aging and AD, positioning ORAs as advantageous for these populations. Indeed, several clinical studies indicate that ORAs are efficacious hypnotics in older persons and dementia patients and, as in adults, are generally well tolerated. ORAs are likely to be more effective when administered early in sleep/wake dysregulation to reestablish good sleep/wake-related behaviors and reduce the accumulation of dementia-associated proteinopathic substrates. Improving sleep in aging and dementia represents a tremendous opportunity to benefit patients, caregivers, and health systems.