Clinical usefulness of dual orexin receptor antagonism beyond insomnia: Neurological and psychiatric comorbidities

Nanoparticles targeting the central circadian clock: Potential applications for neurological disorders

Circadian rhythms and their involvement with various human diseases, including neurological disorders, have become an intense area of research for the development of new pharmacological treatments. The location of the circadian clock machinery in the central nervous system makes it challenging to reach molecular targets at therapeutic concentrations. In addition, a timely administration of the therapeutic agents is necessary to efficiently modulate the circadian clock. Thus, the use of nanoparticles in circadian clock dysfunctions may accelerate their clinical translation by addressing these two key challenges: enhancing brain penetration and/or enabling their formulation in chronodelivery systems. This review describes the implications of the circadian clock in neurological pathologies, reviews potential molecular targets and their modulators and suggests how the use of nanoparticle-based formulations could improve their clinical success. Finally, the potential integration of nanoparticles into chronopharmaceutical drug delivery systems will be described.

Cerebrospinal-fluid Orexin-A levels in different neurocognitive disorders: a comparison study

In the present study, we investigated the differences in cerebrospinal fluid (CSF) orexin-A levels among patients with different neurocognitive disorders, such as mild or moderate to severe Alzheimer's disease (AD; mAD, msAD, respectively), behavioral variants of frontotemporal dementia (bv-FTD), non-fluent primary aphasia (NFPA), and idiopathic normal pressure hydrocephalus (iNPH). A total of 214 participants were evaluated (mAD, 45; msAD, 31; bv-FTD, 12; NFPA, 22; iNPH, 13; non-demented elderly controls, 91). The highest CSF orexin-A levels were found in iNPH patients (263.31 ± 56.89 pg/mL). Patients affected by NFPA (210.86 ± 61.99 pg/mL), iNPH, and msAD (173.04 ± 19.76 pg/mL) showed higher CSF orexin-A concentrations than controls (145.18 ± 27.01pg/mL) (p < 0.001). Bv-FTD (190.12 ± 100.84 pg/mL) and mAD (130.76 ± 21.70 pg/mL) patients showed no significant differences in CSF orexin-A levels compared with controls. mAD patients showed also lower CSF orexin-A concentrations than all other patient groups.In conclusion, orexin-A presents different CSF levels among neurocognitive disorders. The mechanisms underlying this difference vary and may include sleep-wake cycle impairment, behavioral disturbances, and CSF dynamics. The development of drugs that antagonize the orexin system could open a new frontier of research linking orexin neurotransmission to neurocognitive disorders.

Clinical practice guidelines for switching or deprescribing hypnotic medications for chronic insomnia: Results of European neuropsychopharmacology and sleep expert's consensus group

INTRODUCTION

Current guidelines recommend cognitive behavioural therapy for insomnia (CBT-I) as the first-line treatment for chronic insomnia. Pharmacological recommendations by European guidelines for the treatment of insomnia disorder include positive GABAergic modulators such as short and medium acting benzodiazepines and "Z-drugs" (eszopiclone, zaleplon, zolpidem, zopiclone), dual orexin receptor antagonists (DORAs; daridorexant), melatonin receptor agonists (melatonin 2 mg prolonged release - PR). Given the chronic nature of insomnia, the presence of non-responders to some treatments it is often necessary switching between various therapeutic approaches and medications. However, clear guidance regarding safe and effective protocols for switching these medications currently lacks in Europe.

METHOD

To address this gap, we used the RAND/UCLA Appropriateness to evaluate the appropriateness of procedures for switching medications prescribed for insomnia disorder. Following a systematic review of the literature conducted in accordance with the PRISMA guidelines, we then formulated some recommendations.

RESULTS

Twenty-one papers were selected.

CONCLUSIONS

Discontinuation of Hypnotic Benzodiazepines and Z-drugs should be gradual, with dose reductions of 10-25 % each week. Multi-component CBT-I, daridorexant, eszopiclone, and melatonin 2 mg PR were shown to facilitate the gradual discontinuation of hypnotic benzodiazepines/Z-drugs within a cross-tapered program, which can be delayed when necessary. Finally, daridorexant and melatonin 2 mg PR do not require special switching or deprescribing protocols. Several sedative-hypnotic dosage reduction algorithms are proposed in this work for clinical use in real world settings.

Novel Urea-Containing Compounds as Orexin Receptor Agonists for Treating Sleep Disorders, Namely, Narcolepsy, Hypersomnia, and Sleep Apnea Syndrome

Provided herein are novel urea-containing compounds as orexin receptor agonists, pharmaceutical compositions, use of such compounds in treating sleep disorders, namely, narcolepsy, hypersomnia, and sleep apnea syndrome as well as processes for preparing such compounds.

A Preliminary Report on the Effects of Daridorexant in Patients with Comorbid Insomnia and Substance Use Disorders

Background. Sleep disturbances are frequent in patients with substance use disorders (SUDs) and are associated with craving and addiction relapses, leading to increased clinical severity and detrimental outcomes. Daridorexant, a selective dual orexin receptor antagonist, has been approved for persistent insomnia disorder (ID), but specific insights on patients with SUDs are lacking. Methods. This observational, retrospective study investigated the effects of a three-month treatment with daridorexant (50 mg/day) in 41 outpatients with comorbid IDs and SUDs. Improvement in subjective sleep measures, assessed with the Insomnia Severity Index (ISI) and subjective total sleep time, was the primary outcome measure. Changes in anxiety and depression symptoms, quality of life, clinical global severity, and craving were also investigated through the following: Hamilton Anxiety and Depression Rating Scale; Five-item World Health Organization Well-Being Index; Clinical Global Impression Severity Scale; Visual Analog Scale for Craving. Results. All sleep outcomes significantly improved throughout treatment, which was generally safe and well tolerated, with mild and transient drowsiness and sluggishness reported in 21.1% of patients. Similar improvements were observed in psychopathology, quality of life, and craving, and positive correlations were found among ISI scores and anxiety/depression symptoms and craving. An abstinence rate (i.e., absence of any substance use, regardless of the amount, throughout treatment) of 65.8% was also detected at the endpoint. Conclusions. These preliminary findings suggest that daridorexant might represent a promising tool for treating insomnia in patients with SUDs. Identifying interventions effectively targeting insomnia with a good safety/tolerability profile in SUDs is crucial to achieve remission and full functional recovery.

The potential use of daridorexant in eating disorders: beyond the treatment of insomnia?

A strong interplay exists between sleep and dietary habits, and sleep disturbances have been repeatedly documented in individuals with eating disorders (EDs). The orexin system - implicated in sleep regulation, energy homeostasis, and food reward - may represent a mechanist link between sleep alterations and disordered eating behaviors. Daridorexant is a dual orexin receptor antagonist (DORA) recently approved for the treatment of insomnia, with demonstrated efficacy and tolerability. Owing to its action on orexin neurons, the compound represents an intriguing option for addressing both sleep-related and core symptoms of EDs. By inhibiting motor hyperactivity, daridorexant may reduce excessive physical exercise in individuals with anorexia nervosa (AN) restricting type. Additionally, the compound may exert anti-binge effects, suggesting broad applicability in binge ED, bulimia nervosa, and binge/purging AN. In this framework, daridorexant emerges as a promising therapeutic option, offering a multifaceted approach to improving circadian rhythms, energy balance, and overall quality of life in individuals with diverse ED subtypes.

Early experience with the new DORA daridorexant in patients with insomnia disorder and comorbid mental disturbances: Results of a naturalistic study with 3 months follow-up

Insomnia disorder may affect mental health, increasing suicidal risk. Targeting insomnia is crucial in the clinical practice. Sixty-six consecutive patients with insomnia disorder according with the DSM-5-TR criteria were treated with the dual orexin receptor antagonist, daridorexant 50 mg. Baseline (T0), 1 month (T1) and 3 month (T2) evaluations were performed. Insomnia severity (Insomnia Severity Index), mood, anxiety symptoms and suicidal risk (Beck Depression Inventory-II, Young Mania Rating Scale, Self-Reported Anxiety Scale, Suicidal Ideation Scale), dysfunctional insomnia-cognitive factors and pre-sleep arousal (Dysfunctional Beliefs About Sleep, Pre-Sleep Arousal Scale) were evaluated. The final sample included 66 patients (n = 36, 54% females, mean age 60 ± 13.6 years). Most of them, 64%, suffered from insomnia disorder comorbid with unipolar/bipolar depression, anxiety disorders and substance use disorders. Repeated ANOVA analyses showed that Insomnia Severity Index, Dysfunctional Beliefs About Sleep and Pre-Sleep Arousal Scale total score decreased across time (F = 68.818, p < 0.001; F = 47.561, p < 0.001; F = 28.142, p < 0.001, respectively). Similarly, Beck Depression Inventory-II, Self-Reported Anxiety Scale, Young Mania Rating Scale, and Suicidal Ideation Scale significantly decreased over time (p < 0.001). Predictors of insomnia remission (Insomnia Severity Index < 8) at T1 were improvement of Insomnia Severity Index at T1 (F = 60.205, p < 0.001), and improvement of Dysfunctional Beliefs About Sleep at T1 (F = 4.432, p = 0.041). Insomnia remission at T2 was best predicted by improvement of Dysfunctional Beliefs About Sleep at T2 (F = 3.993, p = 0.023). Multiple-regression models showed that clinical improvement of Beck Depression Inventory-II was best predicted by improvement in Dysfunctional Beliefs About Sleep at T1 and T2, manic symptoms by Insomnia Severity Index at T2, anxiety symptoms by Dysfunctional Beliefs About Sleep, Insomnia Severity Index and somatic Pre-Sleep Arousal Scale at T1 and T2. With the caution of a naturalistic design, early experience with daridorexant showed that by targeting insomnia it may be possible to improve not only insomnia symptoms but also comorbid symptoms.

Orexin Receptor Antagonists for the Prevention and Treatment of Alzheimer's Disease and Associated Sleep Disorders

Orexins/hypocretins are neuropeptides produced by the hypothalamic neurons, binding two G-protein coupled receptors (orexin 1 and orexin 2 receptors) and playing a critical role in regulating arousal, wakefulness, and various physiological functions. Given the high prevalence of sleep disturbances in Alzheimer's disease (AD) and their reported involvement in AD pathophysiology, the orexin system is hypothesized to contribute to the disease pathogenesis. Specifically, recent evidence suggests that orexin's influence may extend beyond sleep regulation, potentially affecting amyloid-β and tau pathologies. Dual orexin receptor antagonists (DORAs), namely suvorexant, lemborexant, and daridorexant, demonstrated efficacy in treating chronic insomnia disorder across diverse clinical populations. Considering their stabilizing effects on sleep parameters and emerging evidence of a possible neuroprotective role, these agents represent a promising strategy for AD management. This leading article reviews the potential use of orexin receptor antagonists in AD, particularly focusing on their effect in modulating disease-associated sleep disturbances and clinical outcomes. Overall, clinical studies support the use of DORAs to enhance sleep quality in patients with AD with comorbid sleep and circadian sleep-wake rhythm disorders. Preliminary results also suggest that these compounds might influence AD pathology, potentially affecting disease progression. Conversely, research on selective orexin receptor antagonists in AD is currently limited. Further investigation is needed to explore orexin antagonism not only as a symptomatic treatment for sleep disturbances, but also for its broader implications in modifying AD neurodegeneration, emphasizing mechanisms of action and long-term outcomes.

Novel Compounds as Orexin Receptor Agonists for Treating Sleep Disorders, Namely, Narcolepsy and Hypersomnia

Provided herein are novel compounds as orexin receptor agonists, pharmaceutical compositions, use of such compounds in treating sleep disorders, namely, narcolepsy and hypersomnia, and processes for preparing such compounds.

Daridorexant treatment for chronic insomnia: a real-world retrospective single-center study

INTRODUCTION

Chronic insomnia disorder (CID) significantly impacts well-being and daily functioning. Daridorexant, a double orexin receptor blocker, has shown efficacy in randomized clinical trials and has been recently approved for the treatment of CID in adult patients. This retrospective observational study aimed to describe real-world data on daridorexant effectiveness and safety in adult patients with CID.

METHODS

Consecutive patients initiating on-label daridorexant at the Sleep Medicine Centre, University Hospital of Rome Tor Vergata were enrolled. Baseline and 30-day follow-up (FU) evaluations included patients' and CID characteristics, comorbidities, and clinicians' and patients' subjective ratings of changes with the Clinical and Patient Global Impression-Improvement scores (CGI-Is and PGI-Is), as well as Insomnia Severity Index (ISI) scores in a subgroup of patients.

RESULTS

Sixty-nine patients initiated 50-mg daily dosage. At FU, 58% of both patients and clinicians rated CID as improved on CGI-Is and PGI-Is, with no differences based on comorbidities, sex, or number of previous medications. No significant predictors of CGI-Is and PGI-Is improvement were identified. At FU, ISI scores (n = 24) significantly decreased from 18.25 ± 3.21 to 12.08 ± 6.12 (Z = 8.000; p < 0.001). Of these, eight patients (33.3%) had absence of insomnia symptoms, and no patients reported a worsening in ISI score categories.

CONCLUSIONS

This study suggests daridorexant to be effective and safe in real-world CID treatment whether used as a first-ever treatment, switch, or add-on, as reflected by subjective and objective measures and the absence of serious treatment-related adverse events. Future research on larger cohorts should explore daridorexant potential across diverse patient characteristics.