The efficacy and safety of dual orexin receptor antagonists in primary insomnia: A systematic review and network meta-analysis

Clinical safety of daridorexant in insomnia treatment: Analysis of FDA adverse event reports

OBJECTIVE

Daridorexant, a novel dual orexin receptor antagonist, was approved by the FDA in 2022 for the treatment of insomnia in adults. The aim of this study is to delve into the adverse events (AEs) of daridorexant by analyzing data from the FAERS database, to assess its safety and effectiveness in clinical applications.

METHODS

This study selected data from the FAERS database from the first quarter of 2022 to the third quarter of 2023. Various data analysis methods were used, including the Reporting Odds Ratio (ROR), Proportional Reporting Ratio (PRR), Bayesian Confidence Propagation Neural Network (BCPNN), and Empirical Bayesian Geometric Mean (EBGM), to assess AEs related to daridorexant.

RESULTS

The study analyzed a total of 2,624,030 AE reports, of which 1318 were related to daridorexant. It identified 59 preferred terms (PTs) involving 23 system organ classes (SOCs). Signal mining identified new potential AEs related to daridorexant, including sleep-related psychiatric symptoms (nightmare, abnormal dreams, sleep terror, etc.), emotional and perceptual abnormalities (hallucination, depression, agitation), physiological and behavioral responses (palpitations, dry mouth, energy increased, etc.), suicide risk (suicidal ideation, intentional overdose), and other special concern AEs (tachyphrenia, sleep-related eating disorder, hypersensitivity).

CONCLUSION

Although some new potential AEs have been identified, these findings need further verification in broader datasets and long-term studies due to limitations in data sources and analysis methods. Future research should comprehensively assess the safety and effectiveness of daridorexant, providing more accurate guidance for medical professionals in the treatment of insomnia.

Pain-Insomnia-Depression Syndrome: Triangular Relationships, Pathobiological Correlations, Current Treatment Modalities, and Future Direction

Pain-insomnia-depression syndrome (PIDS) is a complex triad of chronic pain, insomnia, and depression that has profound effects on an individual's quality of life and mental health. The pathobiological context of PIDS involves complex neurobiological and physiological mechanisms, including alterations in neurotransmitter systems and impaired pain processing pathways. The first-line therapeutic approaches for the treatment of chronic pain, depression, and insomnia are a combination of pharmacological and non-pharmacological therapies. In cases where patients do not respond adequately to these treatments, additional interventions such as deep brain stimulation (DBS) may be required. Despite advances in understanding and treatment, there are still gaps in knowledge that need to be addressed. To improve our understanding, future research should focus on conducting longitudinal studies to uncover temporal associations, identify biomarkers and genetic markers associated with PIDS, examine the influence of psychosocial factors on treatment responses, and develop innovative interventions that address the complex nature of PIDS. The aim of this study is to provide a comprehensive overview of these components and to discuss their underlying pathobiological relationships.

The new science of sleep: From cells to large-scale societies

In the past 20 years, more remarkable revelations about sleep and its varied functions have arguably been made than in the previous 200. Building on this swell of recent findings, this essay provides a broad sampling of selected research highlights across genetic, molecular, cellular, and physiological systems within the body, networks within the brain, and large-scale social dynamics. Based on this raft of exciting new discoveries, we have come to realize that sleep, in this moment of its evolution, is very much polyfunctional (rather than monofunctional), yet polyfunctional for reasons we had never previously considered. Moreover, these new polyfunctional insights powerfully reaffirm sleep as a critical biological, and thus health-sustaining, requisite. Indeed, perhaps the only thing more impressive than the unanticipated nature of these newly emerging sleep functions is their striking divergence, from operations of molecular mechanisms inside cells to entire group societal dynamics.

Orexins and primary headaches: an overview of the neurobiology and clinical impact

INTRODUCTION

Primary headaches, including migraines and cluster headaches, are highly prevalent disorders that significantly impact quality of life. Several factors suggest a key role for the hypothalamus, including neuroimaging studies, attack periodicity, and the presence of altered homeostatic regulation. The orexins are two neuropeptides synthesized almost exclusively in the lateral hypothalamus with widespread projections across the central nervous system. They are involved in an array of functions including homeostatic regulation and nociception, suggesting a potential role in primary headaches.

AREAS COVERED

This review summarizes current knowledge of the neurobiology of orexins, their involvement in sleep-wake regulation, nociception, and functions relevant to the associated symptomology of headache disorders. Preclinical reports of the antinociceptive effects of orexin-A in preclinical models are discussed, as well as clinical evidence for the potential involvement of the orexinergic system in headache.

EXPERT OPINION

Several lines of evidence support the targeted modulation of orexinergic signaling in primary headaches. Critically, orexins A and B, acting differentially via the orexin 1 and 2 receptors, respectively, demonstrate differential effects on trigeminal pain processing, indicating why dual-receptor antagonists failed to show clinical efficacy. The authors propose that orexin 1 receptor agonists or positive allosteric modulators should be the focus of future research.

A retrospective clinical practice study comparing the usefulness of dual-orexin receptor antagonists and a melatonin receptor agonist in patients switching from long-term benzodiazepine receptor agonists

STUDY OBJECTIVES

Although novel hypnotics have recently emerged, there are currently no data comparing the clinical potency of benzodiazepine receptor agonists (BZRAs) and novel hypnotics, or the effectiveness of different methods of switching between them. This study examined how novel hypnotics might help reduce BZRA use in real-world practice.

METHODS

289 patients with psychiatric disorders who took BZRAs for over 1 year before switching to either of 2 dual-orexin receptor antagonists (DORAs; suvorexant [SUV] or lemborexant [LEM]) or a melatonin receptor agonist (ramelteon [RMT]) were enrolled. We collected data on BZRAs at baseline and 3 months after commencement of SUV/LEM/RMT.

RESULTS

Significant reductions in BZRAs were observed for all 3 agents: -4.10, -2.80, and -1.65 mg in diazepam-equivalent doses in the SUV, LEM, and RMT groups, respectively. Dose reduction was significantly greater in the DORA than the RMT group (F = 15.053, P < .001). Within the DORA group, dose reduction was significantly greater in patients taking SUV than those taking LEM (F = 4.337, P = .043). The switching success rate did not differ among the switching methods for any of the hypnotics.

CONCLUSIONS

The reduction rate of BZRAs achieved by the switch fell into their equivalent-potency range estimated from clinical trials. The results suggest that DORAs can replace approximately 1 tablet of a BZRA. The difference in dose reduction between DORAs and RMT reflected the greater sleeping potency of the DORAs, whereas that between SUV and LEM might have reflected patient backgrounds: patients taking LEM may have been more strongly dependent on BZRAs.

CITATION

Tachibana M, Kanahara N, Oda Y, Hasegawa T, Kimura A, Iyo M. A retrospective clinical practice study comparing the usefulness of dual-orexin receptor antagonists and a melatonin receptor agonist in patients switching from long-term benzodiazepine receptor agonists. J Clin Sleep Med. 2024;20(4):603-613.

Parasomnia induced by lemborexant: a case report

Lemborexant, an orexin receptor antagonist, is effective not only for sleep disorders but also for preventing and treating delirium. To date, no complex sleep-related behaviors due to lemborexant have been reported. Herein, we present the case of a 69-year-old male patient who was hospitalized for oral floor and tongue cancer and developed delirium after surgery; however, upon lemborexant dosage increase, used to treat insomnia, he developed abnormal nocturnal behavior. This symptom rapidly improved when lemborexant was discontinued. Distinguishing parasomnia from delirium is important because the treatment of these two conditions differs. Although rapid eye movement sleep behavior or sleepwalking was the cause of this parasomnia, a definitive diagnosis could not be established. If qualitatively distinct abnormal behavior is observed compared to delirium after increasing lemborexant dosage, the possibility of parasomnia should be considered.

Recent advances in understanding of sleep disorders and disturbances for dementia risk and prevention

PURPOSE OF REVIEW

To synthesise the recent work examining the relationship between sleep disturbances and dementia, emphasising studies involving individuals with mild cognitive impairment (MCI) or Alzheimer's disease (AD) and/or those investigating AD biomarkers. Additionally, we provide an update on recent interventions targeting sleep-related issues in older adults with MCI or AD.

RECENT FINDINGS

Various studies have examined obstructive sleep apnoea, sleep duration, and circadian alterations in relation to Alzheimer's pathology and dementia risk, with an emerging body of evidence suggesting that cardiovascular disease, hypertension, glymphatic function, and inflammation might serve as plausible pathophysiological mechanisms contributing to dementia during critical brain periods. Conversely, recent studies investigating insomnia have produced disparate results. Regarding intervention studies, the scarcity of prospective randomised control trials poses a challenge in establishing the benefits of addressing sleep disorders and disturbances.

SUMMARY

Recent work examining the pathophysiological links between sleep and dementia is strongest for obstructive sleep apnoea and sleep duration, while findings in insomnia studies exhibit inconsistency, possibly due to varied associations with dementia among different insomnia subtypes. It is apparent that more longitudinal studies examining the underlying pathophysiological mechanisms are necessary, alongside more rigorous clinical trials. Although some trials are underway in this field, there is still scarcity in trials examining interventions for circadian disturbances.

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

Orexin is a neurotransmitter produced by a small group of hypothalamic neurons. Besides its well-known role in the regulation of the sleep-wake cycle, the orexin system was shown to be relevant in several physiological functions including cognition, mood and emotion modulation, and energy homeostasis. Indeed, the implication of orexin neurotransmission in neurological and psychiatric diseases has been hypothesized via a direct effect exerted by the projections of orexin neurons to several brain areas, and via an indirect effect through orexin-mediated modulation of sleep and wake. Along with the growing evidence concerning the use of dual orexin receptor antagonists (DORAs) in the treatment of insomnia, studies assessing their efficacy in insomnia comorbid with psychiatric and neurological diseases have been set in order to investigate the potential impact of DORAs on both sleep-related symptoms and disease-specific manifestations. This narrative review aimed at summarizing the current evidence on the use of DORAs in neurological and psychiatric conditions comorbid with insomnia, also discussing the possible implication of modulating the orexin system for improving the burden of symptoms and the pathological mechanisms of these disorders. Target searches were performed on PubMed/MEDLINE and Scopus databases and ongoing studies registered on Clinicaltrials.gov were reviewed. Despite some contradictory findings, preclinical studies seemingly support the possible beneficial role of orexin antagonism in the management of the most common neurological and psychiatric diseases with sleep-related comorbidities. However, clinical research is still limited and further studies are needed for corroborating these promising preliminary results.

Clinical safety and narcolepsy-like symptoms of dual orexin receptor antagonists in patients with insomnia: a systematic review and meta-analysis

STUDY OBJECTIVES

Dual orexin receptor antagonists (DORAs) are emerging treatments for insomnia. This meta-analysis study aimed to assess the safety of FDA-approved DORAs (suvorexant, lemborexant, and daridorexant), focusing on narcolepsy-like symptoms associated with these drugs.

METHODS

Five prominent databases were searched to identify randomized controlled trials (RCTs) on this topic. Primary safety outcomes included treatment-emergent adverse events (TEAEs), treatment-related TEAEs, TEAEs leading to discontinuation, and serious TEAEs. Excessive daytime sleepiness (EDS), sleep paralysis, and hallucinations were categorized as adverse events (AEs)-related narcolepsy-like symptoms.

RESULTS

Eleven RCTs with 7703 patients were included. DORAs were associated with a higher risk of TEAEs (risk ratio [RR], 1.09; 95% confidence interval [CI], 1.03 to 1.15) and treatment-related TEAEs (RR, 1.69; 95% CI: 1.49 to 1.92) when compared to placebo. The DORA group exhibited a significantly higher risk of EDS (RR, 2.15; 95% CI: 1.02 to 4.52) and sleep paralysis (RR, 3.40; 95% CI: 1.18 to 9.80) compared to the placebo group.

CONCLUSION

This meta-analysis achieved a comparative evaluation of the clinical safety and tolerability of FDA-approved DORAs for primary insomnia, specifically focusing on AEs-related narcolepsy-like symptoms. This study contributes to understanding the safety profile of FDA-approved DORAs for treating insomnia.

Orexin-A/OX1R is involved in regulation of autophagy to promote cortisol secretion in adrenocortical cell

BACKGROUND

Hypercortisolism has emerged as a prominent clinical condition worldwide caused by biochemical cortisol excess in patients, and optimization treatment is needed urgently in the clinic. Previously, we observed that orexin-A/orexin type 1 receptor (OX1R) promoted cell proliferation, inhibited apoptosis, and increased cortisol release in adrenocortical cells. However, the functions of orexin-A/OX1R on autophagy and its molecular mechanism are not known.

METHODS

Transmission electron microscopy and confocal microscope were performed to detect autophagosomes. Western blot were performed to detect autophagy proteins. The cortisol concentration was assessed with an ELISA.

FINDINGS

Our data demonstrated that orexin-A/OX1R activated the mammalian target of rapamycin/p70 ribosomal protein S6 kinase-1 pathway, thereby inhibiting autophagy in H295R cells and Y-1 cells. Furthermore, the orexin-A/OX1R-mediated suppression of autophagy played a crucial role in cortisol secretion. Mechanistically, the expression of 3β-hydroxysteroid dehydrogenase/isomerase, the rate-limiting enzyme in cortisol synthesis, was increased with autophagy inhibition mediated by orexin-A/OX1R.

INTERPRETATION

This study provided the evidence that orexin-A/OX1R participated in modulating mTOR/p70S6K1/autophagy signaling pathway to promote cortisol secretion in adrenocortical cell. The findings suggest the mechanistic basis for disorders of cortisol secretion, providing the potential therapeutic targets for hypercortisolism treatment. FUND: This work was supported by National Natural Science Foundation of China (32170603, 31871286), the Doctoral Start-up Foundation of Liaoning Province (20180540008, 2019-BS-298), the Natural Science Foundation of Liaoning Province (2019-ZD-0779), and Shenyang Science and Technology Plan Fund Projects (21-173-9-28).

Impact of zolpidem and lemborexant on sleep and morning symptoms when used as a single dose for polysomnography

This study evaluated the effect of zolpidem and lemborexant on sleep and morning symptoms in patients undergoing type-1 polysomnography for suspected sleep-disordered breathing based on questionnaires and polysomnography results. We enrolled 127 patients (lemborexant: N = 57, zolpidem: N = 25, without hypnotics: N = 45). Rapid eye movement sleep in patients on lemborexant was higher than that in patients without hypnotics (P = 0.02). Frequency of unsteadiness in the morning was higher in patients on zolpidem than that in patients without hypnotics (P = 0.04), which remained after adjustment for potential confounders (P = 0.03). Low-dose lemborexant might be suitable when administered as a single dose during polysomnography.

Resting phase-administration of lemborexant ameliorates sleep and glucose tolerance in type 2 diabetic mice

Sleep disorders are associated with increased risk of obesity and type 2 diabetes. Lemborexant, a dual orexin receptor antagonist (DORA), is clinically used to treat insomnia. However, the influence of lemborexant on sleep and glucose metabolism in type 2 diabetic state has remained unknown. In the present study, we investigated the effect of lemborexant in type 2 diabetic db/db mice exhibiting both sleep disruption and glucose intolerance. Single administration of lemborexant at the beginning of the light phase (i.e., resting phase) acutely increased total time spent in non-rapid eye movement (NREM) and REM sleep in db/db mice. Durations of NREM sleep-, REM sleep-, and wake-episodes were also increased by this administration. Daily resting-phase administration of lemborexant for 3-6 weeks improved glucose tolerance without changing body weight and glucose-stimulated insulin secretion in db/db mice. Similar improvement of glucose tolerance was caused by daily resting-phase administration of lemborexant in obese C57BL/6J mice fed high fat diet, whereas no such effect was observed in non-diabetic db/m+ mice. Diabetic db/db mice treated daily with lemborexant exhibited increased locomotor activity in the dark phase (i.e., awake phase), although they did not show any behavioral abnormality in the Y-maze, elevated plus maze, and forced swim tests. These results suggest that timely promotion of sleep by lemborexant improved the quality of wakefulness in association with increased physical activity during the awake phase, and these changes may underlie the amelioration of glucose metabolism under type 2 diabetic conditions.

The orexin story and orexin receptor antagonists for the treatment of insomnia

Insomnia is present in up to one third of the adult population worldwide, and it can present independently or with other medical conditions such as mental, metabolic, or cardiovascular diseases, which highlights the importance of treating this multifaceted disorder. Insomnia is associated with an abnormal state of hyperarousal (increased somatic, cognitive, and cortical activation) and orexin has been identified as a key promotor of arousal and vigilance. The current standards of care for the treatment of insomnia recommend non-pharmacological interventions (cognitive behavioural therapy) as first-line treatment and, if behavioural interventions are not effective or available, pharmacotherapy. In contrast to most sleep medications used for decades (benzodiazepines and 'Z-drugs'), the new orexin receptor antagonists do not modulate the activity of γ-aminobutyric acid receptors, the main inhibitory mechanism of the central nervous system. Instead, they temporarily block the orexin pathway, causing a different pattern of effects, e.g., less morning or next-day effects, motor dyscoordination, and cognitive impairment. The pharmacokinetic/pharmacodynamic properties of these drugs are the basis of the different characteristics explained in the package inserts, including the recommended starting dose. Orexin receptor antagonists seem to be devoid of any dependence and tolerance-inducing effects, rendering them a viable option for longer-term treatment. Safety studies did not show exacerbation of existing respiratory problems, but more real-world safety and pharmacovigilance experience is needed. This review provides an overview of the orexin history, the mechanism of action, the relation to insomnia, and key features of available drugs mediating orexin signalling.

Comparative efficacy of hypnotics in young and middle-aged adults with insomnia: a systematic review and network meta-analysis

OBJECTIVE/BACKGROUND

Insomnia is highly prevalent in modern society. However, the hierarchical selection of hypnotics in young and middle-aged adults with insomnia remains unclear. We aimed to compare the efficacy and daytime drowsiness associated with different hypnotics for treating insomnia in young and middle-aged adults.

METHODS

We searched Embase, PubMed, Cochrane Library, and ProQuest Dissertations and Theses A&I databases from inception until December 15, 2021. We also manually searched reference lists and relevant publications. The literature search, data collection, and risk of bias evaluation were all carried out separately by pairs of reviewers. We included randomized control trials (RCTs) that compared hypnotics approved by the Food and Drug Administration. The R and Stata software were both used to perform the meta-analysis.

RESULTS

In total, 117 RCTs comprising 22,508 participants with the age of 18 to 65 years were included. Assessment of the efficacy of the hypnotics and adverse events (drowsiness) revealed that zolpidem improved all objective sleep parameters (oTST, oSOL, oWASO, and oSE), zopiclone increased oTST and oSE and reduced oSOL, and daridorexant increased oTST and reduced oWASO. Regarding subjective sleep outcomes, zolpidem exhibited beneficial effects on sTST, sSOL, and sWASO. Zaleplon reduced sSOL, and zopiclone was the recommended hypnotic for improving SQ. Zolpidem was associated with drowsiness effect (odds ratio = 1.82; 95% confidence interval = 1.25 to 2.65). The results of sensitivity analysis remained unchanged after the exclusion of studies reporting long-term effects.

CONCLUSION

Zolpidem is recommended for managing sleep-onset insomnia and sleep maintenance insomnia but should be used with caution because of daytime drowsiness effects. Daridorexant is recommended as a promising agent for managing sleep maintenance insomnia.

Pharmacological management of co-morbid obstructive sleep apnoea and insomnia

INTRODUCTION

Clinical presentation of both insomnia and obstructive sleep apnea (COMISA) is common. Approximately 30% of clinical cohorts with OSA have insomnia symptoms and vice versa. The underlying pathophysiology of COMISA is multifactorial. This poses a complex clinical challenge. Currently, there are no clinical guidelines or recommendations outside of continuous positive airway pressure (CPAP) therapy and cognitive behavioral therapy for insomnia (CBTi). Clinically translatable precision medicine approaches to characterize individual causes or endotypes may help optimize future pharmacological management of COMISA.

AREAS COVERED

This review article provides an up-to-date account of COMISA and its consequences, the underlying pathophysiology of sleep apnea, insomnia and COMISA, current treatment approaches and limitations, pharmacotherapy targets and future priorities.

EXPERT OPINION

There are multiple promising emerging therapies, but clinical trial data specifically in COMISA populations are lacking. This is a priority for future investigation to inform development of evidence-based guidelines. Pharmacotherapies, particularly for insomnia, do not target the underlying causes of the disorder thus, are indicated for short-term use only and should remain second line. Future multidisciplinary research should be directed toward the multifactorial nature of COMISA and the challenges of adapting COMISA treatment in clinical practice and overcoming the practical barriers that health-care providers and consumers encounter.

Daridorexant: Comprehensive Review of A New Oral Agent for the Treatment of Insomnia

OBJECTIVE

To review the current pharmacology, pharmacokinetics/pharmacodynamics, safety, and efficacy of daridorexant in patients with insomnia.

DATA SOURCES

A literature search of PubMed (March 1, 2018, to October 19, 2022) and ClinicalTrials.gov search was conducted using the following terms: daridorexant and ACT-541468. Additional articles were identified by hand from references.

STUDY SELECTION AND DATA EXTRACTION

We included English-language articles evaluating daridorexant pharmacology, efficacy, or safety in humans for the management of insomnia.

DATA SYNTHESIS

Daridorexant has a peak plasma concentration of 1-2 hours, terminal half-life of 8 hours, and absolute bioavailability of 61%. Wake after sleep onset (WASO) significantly decreased from baseline to months 1 and 3 in daridorexant 25 (-18.40 and -22.97 min, P < 0.0001) and 50 mg (-28.98 and -29.41 min, P < 0.0001) groups compared with placebo. Latency to persistent sleep (LPS) significantly decreased from baseline to months 1 and 3 for daridorexant 25 mg (-28.17 and -30.73 min, P = 0.0005 and P = 0.0015) and 50 mg (-31.20 and -34.80 min, P < 0.0001).

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE IN COMPARISON TO EXISTING AGENTS

Daridorexant can be administered in diverse patient populations because of its tolerability and favorable safety profile. However, due to the lack of large scale studies that directly compare dual orexin receptor antagonists (DORAs), there is not enough data to recommend 1 DORA over another.

CONCLUSIONS

Daridorexant is well tolerated and has demonstrated significant reductions in LPS and WASO in the treatment of insomnia in adult patients.

Role of the orexin system in the bidirectional relation between sleep and epilepsy: New chances for patients with epilepsy by the antagonism to orexin receptors?

Epilepsy is a common neurological disorder, affecting patients of all ages, reducing the quality of life, and associated with several comorbidities. Sleep impairment is a frequent condition in patients with epilepsy (PWE), and the relation between sleep and epilepsy has been considered bidirectional, as one can significantly influence the other, and vice versa. The orexin system was described more than 20 years ago and is implicated in several neurobiological functions other than in controlling the sleep-wake cycle. Considering the relation between epilepsy and sleep, and the significant contribution of the orexin system in regulating the sleep-wake cycle, it is conceivable that the orexin system may be affected in PWE. Preclinical studies investigated the impact of the orexin system on epileptogenesis and the effect of orexin antagonism on seizures in animal models. Conversely, clinical studies are few and propose heterogeneous results also considering the different methodological approaches to orexin levels quantification (cerebrospinal-fluid or blood samples). Because orexin system activity can be modulated by sleep, and considering the sleep impairment documented in PWE, the recently approved dual orexin receptor antagonists (DORAs) have been suggested for treating sleep impairment and insomnia in PWE. Accordingly, sleep improvement can be a therapeutic strategy for reducing seizures and better managing epilepsy. The present review analyzes the preclinical and clinical evidence linking the orexin system to epilepsy, and hypothesizes a model in which the antagonism to the orexin system by DORAs can improve epilepsy by both a direct and a sleep-mediated (indirect) effect.

Different doses of dual orexin receptor antagonists in primary insomnia: a Bayesian network analysis

Background: Systematic comparisons of the doses of the Food and Drug Administration (FDA)-approved dual orexin receptor antagonists (DORAs) for people with insomnia are limited. Methods: PubMed, Embase, Cochrane Library, and Clinicaltrials. gov were systematically searched to identify relevant studies published before 31 October 2022. We assessed the certainty of evidence using the confidence in network meta-analysis (CINeMA) framework. Results: We pooled 7257 participants from 9 randomized controlled trials (RCTs). Moderate to high certainty evidence demonstrated suvorexant (20 and 40 mg) and daridorexant (10 and 50 mg) as the most effective in latency to persistent sleep (LPS) reduction. Lemborexant at 5 and 10 mg was the most effective in subjective sleep onset time (sTSO) reduction. For wake time after sleep onset (WASO), all drugs except daridorexant 5 mg were more effective than placebo. Lemborexant 5 mg was among the best in subjective WASO (sWASO) (moderate to high certainty) and had the highest surface under the curve ranking area (SUCRA) values for sWASO (100%). For total sleep time (TST), suvorexant and daridorexant, except the respective minimum doses, were more effective than placebo, while suvorexant 40 mg and lemborexant 10 mg may have been the most effective for subjective TST (sTST) (low to very low certainty). Suvorexant 40 mg (RR 1.09), suvorexant 80 mg (RR 1.65), and daridorexant 25 mg (RR 1.16) showed a higher safety risk than placebo. Conclusion: Suvorexant 20 mg, lemborexant 5 mg, lemborexant 10 mg, and daridorexant 50 mg represent suitable approaches for insomnia. Clinical Trial Registration: clinicaltrials.gov, PROSPERO (CRD42022362655).

Cannabidiol as a candidate pharmacotherapy for sleep disturbance in alcohol use disorder

Among individuals with alcohol use disorder (AUD), it is estimated that the majority suffer from persistent sleep disturbances for which few candidate medications are available. Our aim wass to critically review the potential for cannabidiol (CBD) as a treatment for AUD-induced sleep disturbance. As context, notable side effects and abuse liability for existing medications for AUD-induced sleep disturbance reduce their clinical utility. CBD modulation of the endocannabinoid system and favorable safety profile have generated substantial interest in its potential therapeutic use for various medical conditions. A number of preclinical and clinical studies suggest promise for CBD in restoring the normal sleep-wake cycle and in enhancing sleep quality in patients diagnosed with AUD. Based on its pharmacology and the existing literature, albeit primarily preclinical and indirect, CBD is a credible candidate to address alcohol-induced sleep disturbance. Well-designed RCTs will be necessary to test its potential in managing this challenging feature of AUD.

Dual orexin receptor antagonists for the treatment of insomnia: systematic review and network meta-analysis

BACKGROUND

 Several randomized clinical trials (RCTs) have shown that dual orexin receptor antagonists (DORAs) are effective in the treatment of chronic insomnia. However, the superiority of one particular DORA over the others remains unclear.

OBJECTIVE

 To perform a network meta-analysis to evaluate the efficacy of different DORAs in patients with chronic insomnia.

METHODS

 The Medline, Embase, and Cochrane Central databases were searched for RCTs that compared DORA with placebo in patients ≥ 18 years of age with a diagnosis of insomnia disorder. We pooled outcomes for wake time after sleep onset (WASO), latency to persistent sleep (LPS), total sleep time (TST), and adverse events (AEs).

RESULTS

 We included 10 RCTs with 7,806 patients, 4,849 of whom received DORAs as the intervention. Overall, we found that DORAs were associated with the improvement of all analyzed efficacy outcomes. Concerning TST, an apparent dose-dependent pattern was noticed, with higher doses relating to a longer TST. Lemborexant 10mg provided the largest reduction in WASO (at month 1) in minutes (standardized mean difference [SMD] = -25.40; 95% confidence interval [95%CI] = -40.02--10.78), followed by suvorexant 20/15mg (SMD = -25.29; 95%CI = -36.42--14.15), which also appeared to provide the largest decrease in long-term WASO (SMD = -23.70; 95%CI = -35.89--11.51). The most frequent AEs were somnolence, nasopharyngitis, and headache, with rates of up to 14.8%.

CONCLUSION

 Our results suggest that DORAs are associated with greater efficacy when compared with placebo in the treatment of insomnia, a complex 24-hour sleep disorder. Additionally, dosing might play an important role in the management of chronic insomnia.

The Comparative Effectiveness and Safety of Insomnia Drugs: A Systematic Review and Network Meta-Analysis of 153 Randomized Trials

BACKGROUND

Pharmacological treatment is common in practice and widely used for the management of insomnia. However, evidence comparing the relative effectiveness, safety, and certainty of evidence among drug classes and individual drugs for insomnia are still lacking. This study aimed to determine the relative effectiveness, safety, and tolerability of drugs for insomnia.

METHODS

In this systematic review and network meta-analysis we systematically searched PubMed, Embase, Cochrane Central Register of Controlled Trials, PsycINFO, and ClinicalTrials.gov, from inception to January 10, 2022 to identify randomized controlled trials that compared insomnia drugs with placebo or an active comparator in adults with insomnia. We conducted random-effects frequentist network meta-analyses to summarize the evidence, and used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach to assess the certainty, categorize interventionsand present the findings.

RESULTS

A total of 148 articles met our eligibility criteria; these included 153 trials which enrolled 46,412 participants and assessed 36 individual drugs from eight drug classes. Compared with placebo, both subjectively and objectively measured total sleep time were significantly improved with non-benzodiazepine (subjective: mean difference [MD] 25.07, 95% confidence interval [CI] 15.49-34.64, low certainty; objective: MD 22.34, 95% CI 7.64-37.05, high certainty), antidepressants (subjective: MD 54.40, 95% CI 34.96-75.83, low certainty; objective: MD 35.64, 95% CI 13.05-58.24, high certainty), and orexin receptor antagonists (subjective: MD 21.62, 95% CI 0.84-42.40, high certainty; objective: MD 31.81, 95% CI 2.66-60.95, high certainty); of which doxepin, almorexant, suvorexant, and lemborexant were among the relatively effective drugs with relatively good tolerability and lower risks of any adverse events (AEs). Both subjectively and objectively measured sleep onset latency were significantly shortened with non-benzodiazepines (subjective: MD - 10.12, 95% CI - 13.84 to - 6.40, moderate certainty; objective: MD - 12.11, 95% CI - 19.31 to - 4.90, moderate certainty) and melatonin receptor agonists (subjective: MD - 7.73, 95% CI - 15.21 to - 0.26, high certainty; objective: MD - 7.04, 95% CI - 12.12 to - 1.95, moderate certainty); in particular, zopiclone was among the most effective drugs with a lower risk of any AEs but worse tolerability. Non-benzodiazepines could significantly decrease both subjective and objective measured wake time after sleep onset (subjective: MD - 16.67, 95% CI - 21.79 to - 11.56, moderate certainty; objective: MD - 13.92, 95% CI - 22.71 to - 5.14, moderate certainty).

CONCLUSIONS

Non-benzodiazepines probably improve total sleep time, sleep onset latency, and wake time after sleep onset. Other insomnia drug classes and individual drugs also showed potential benefits in improving insomnia symptoms. However, the choice of insomnia drugs should be based on the phenotype of insomnia presented, as well as each drug's safety and tolerability. Protocol registration PROSPERO (CRD42019138790).

Comparative efficacy and safety of suvorexant and lemborexant for insomnia treatment

Aim

Although suvorexant and lemborexant, which have orexin receptor antagonist activity, are used as sleep medications in Japan, no report has directly compared their efficacy and safety. This study compared the efficacy and safety of the drugs.

Methods

This retrospective cohort study included patients who presented to the Outpatient Department of Psychiatry at Tottori University Hospital between December 1, 2020, and December 31, 2021. Information was obtained from 108 patients who were newly treated with suvorexant or lemborexant. Data were analyzed after excluding one case of discontinuation due to a post-administration allergic reaction. Improvement in sleep status after administration was assessed retrospectively from medical records by using the Clinical Global Impressions-Improvement (CGI-I) Scale, which is a subscale of the Clinical Global Impressions (CGI) Scale. The incidence of side-effects was obtained from the medical records of the patient's first visit after administration.

Results

There was no significant difference between the CGI-I scores in the suvorexant (mean [SD], 3.05 [0.93]) and lemborexant groups (mean [SD], 3.38 [0.83]) (p = 0.10). The incidence of side-effects with continued treatment was not significantly different between the suvorexant group (12.5%) and the lemborexant group (2.9%) (p = 0.10). Patients who switched from suvorexant to lemborexant had CGI-I scores ≤4, and no side-effects were observed after switching to lemborexant.

Conclusion

There was no difference in effectiveness between suvorexant and lemborexant. However, lemborexant might cause side-effects less frequently than suvorexant, at least in the early stages of treatment.

Daridorexant for the treatment of insomnia disorder: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Daridorexant is a novel dual orexin receptor antagonist that has shown efficacy as a treatment for insomnia in multiple randomized clinical trials. However, the efficacy and safety of daridorexant for treatment of insomnia disorder has not been characterized comprehensively in the literature. Therefore, we performed a meta-analysis of available studies. We performed a meta-analysis to systematically evaluate the efficacy and safety of daridorexant for treatment of insomnia disorder.

METHODS

MEDLINE, Embase, Cochrane Library, and Clinicaltrials.gov for randomized controlled trials were systematically searched up to February 2022. Relative risk and standard mean difference were used to evaluate clinical outcomes.

RESULTS

We pooled 2271 patients from 4 randomized clinical trials, and evaluated efficacy endpoints. We found that 50 mg of daridorexant was superior to placebo for 4 efficacy outcomes including wake time after sleep onset, latency to persistent sleep, subjective total sleep time, and Insomnia Daytime Symptoms and Impacts Questionnaire domain score (P < .05). In addition, there were no significant differences (P > .05) in adverse events between daridorexant and placebo.

CONCLUSIONS

Different dosages of daridorexant were tested for treatment of insomnia; however, 5 and 10 mg are not available because of issues of suboptimal effectiveness. Daridorexant showed better efficacy and safety for treatment of insomnia disorder at doses of 25 and 50 mg.

The future of psychopharmacology: a critical appraisal of ongoing phase 2/3 trials, and of some current trends aiming to de-risk trial programmes of novel agents

Despite considerable progress in pharmacotherapy over the past seven decades, many mental disorders remain insufficiently treated. This situation is in part due to the limited knowledge of the pathophysiology of these disorders and the lack of biological markers to stratify and individualize patient selection, but also to a still restricted number of mechanisms of action being targeted in monotherapy or combination/augmentation treatment, as well as to a variety of challenges threatening the successful development and testing of new drugs. In this paper, we first provide an overview of the most promising drugs with innovative mechanisms of action that are undergoing phase 2 or 3 testing for schizophrenia, bipolar disorder, major depressive disorder, anxiety and trauma-related disorders, substance use disorders, and dementia. Promising repurposing of established medications for new psychiatric indications, as well as variations in the modulation of dopamine, noradrenaline and serotonin receptor functioning, are also considered. We then critically discuss the clinical trial parameters that need to be considered in depth when developing and testing new pharmacological agents for the treatment of mental disorders. Hurdles and perils threatening success of new drug development and testing include inadequacy and imprecision of inclusion/exclusion criteria and ratings, sub-optimally suited clinical trial participants, multiple factors contributing to a large/increasing placebo effect, and problems with statistical analyses. This information should be considered in order to de-risk trial programmes of novel agents or known agents for novel psychiatric indications, increasing their chances of success.

Targeting Orexin Receptors for the Treatment of Insomnia: From Physiological Mechanisms to Current Clinical Evidence and Recommendations

After a detailed description of orexins and their roles in sleep and other medical disorders, we discuss here the current clinical evidence on the effects of dual (DORAs) or selective (SORAs) orexin receptor antagonists on insomnia with the aim to provide recommendations for their further assessment in a context of personalized and precision medicine. In the last decade, many trials have been conducted with orexin receptor antagonists, which represent an innovative and valid therapeutic option based on the multiple mechanisms of action of orexins on different biological circuits, both centrally and peripherally, and their role in a wide range of medical conditions which are often associated with insomnia. A very interesting aspect of this new category of drugs is that they have limited abuse liability and their discontinuation does not seem associated with significant rebound effects. Further studies on the efficacy of DORAs are required, especially on children and adolescents and in particular conditions, such as menopause. Which DORA is most suitable for each patient, based on comorbidities and/or concomitant treatments, should be the focus of further careful research. On the contrary, studies on SORAs, some of which seem to be appropriate also in insomnia in patients with psychiatric diseases, are still at an early stage and, therefore, do not allow to draw definite conclusions.

Orexin Receptor Antagonists in the Treatment of Depression: A Leading Article Summarising Pre-clinical and Clinical Studies

The orexin (hypocretin) system comprises two neuropeptides (orexin-A and orexin-B) and two G-protein coupled receptors (the orexin type 1 and the orexin type 2 receptor). The system regulates several biological functions including appetite, the sleep-wake cycle, the stress response, and motivation and reward processing. Dysfunction of the orexin system has been implicated in the pathophysiology of depression in human and animal studies, although the exact nature of this dysfunction remains unclear. Orexin receptor antagonists (ORAs) are a class of compounds developed for the treatment of insomnia and have demonstrated efficacy in this area. Three dual orexin receptor antagonists (DORAs) have received licences for treatment of primary insomnia and some ORAs have since been investigated as potential treatments for major depressive disorder (MDD). In this leading article, we summarise the existing literature on use of ORAs in depression, in pre-clinical and clinical studies. In rodent models of depression, investigated ORAs have included the DORA almorexant and TCS1102, the selective orexin 1 receptor antagonists SB334867 and SB674042 and the selective orexin 2 receptor antagonists LSN2424100, MK-1064 and TCS-OX2-29. These pre-clinical studies suggest a possible antidepressant effect of systemic DORA treatment, however the evidence from selective ORAs is conflicting. To date, four published RCTs (one with the DORA filorexant and three with the selective orexin 2 receptor antagonist seltorexant), have compared an ORA with placebo in the treatment of MDD. Only one of these demonstrated a statistically significant difference relative to placebo.

Comparative risk of fracture in community-dwelling older adults initiating suvorexant versus Z-drugs: Results from LIFE study

BACKGROUND

An increased risk of fracture has been reported in older adults taking hypnotics. However, few studies have reported the comparative safety of hypnotics with different mechanisms of action. We examined the risk of fracture in older adults initiating suvorexant compared to those initiating Z-drugs.

METHODS

We conducted a retrospective cohort study using a claims database within a longevity improvement and fair evidence (LIFE) study in Japan (1.5 million beneficiaries). People aged ≥65 years were included in this study. Exposure was defined as the initiation of either suvorexant or Z-drugs (eszopiclone, zolpidem, or zopiclone). The evaluated outcomes were hip fracture and all-cause fracture requiring hospitalization. We used inverse probability of treatment weights to adjust for confounding and followed the incidence of the outcome for three different periods: 30, 90, and 365 days. Cox proportional hazards models were fitted to the weighted population to estimate hazard ratios (HRs). Sensitivity analyses were performed with narrowed outcome definitions and inverse probability of censoring weights.

RESULTS

We identified 16,148 suvorexant new users and 54,327 Z-drugs new users. During the 30-day follow-up, 21 (16.6 events per 1000 person-years) and 53 hip fractures (12.2 events per 1000 person-years) were identified among suvorexant and Z-drugs new users, respectively (HR: 1.01, 95% confidence interval [CI]: 0.58-1.76). The analysis for all-cause fracture showed an HR of 1.03 (95% CI: 0.78-1.36). Extended follow-up (90 and 365 days) showed similar results for both outcomes. Sensitivity analyses showed consistent results except for an increased risk of all-cause fracture requiring surgery (HR: 1.41, 95% CI: 0.87-2.29) during the 30-day follow-up.

CONCLUSIONS

This is the first study to show that suvorexant has a generally comparable risk of fracture as compared to Z-drugs. Further research is needed to investigate the potential short-term increased risk of all-cause fracture requiring surgery among suvorexant initiators.

Orexin Receptor Antagonists and Insomnia

PURPOSE OF REVIEW

We review recent evidence on the use of orexin receptor antagonists (ORAs) for treating insomnia. We evaluate studies on five dual ORAs and one selective ORA.

RECENT FINDINGS

Research on suvorexant in recent years gradually focus on comorbid insomnia, while lemborexant and daridorexant were still being validated in primary insomnia. Almorexant is now mainly used as a commercial specific inhibitor of the orexin system in animal studies due to safety issues. Although filorexant has also shown a certain sleep-promoting effect, there are few clinical or experimental studies on sleep-related aspects of filorexant in recent years. As for selective ORAs, orexin receptor 2 antagonist seltorexant still has not yet reached phase 3. High-quality clinical trials in insomnia populations are needed which directly compare authorized ORAs and investigate non-approved ORAs, the use of ORAs in comorbid insomnia, and the orexin signaling system pathophysiology in insomnia.

Comparative efficacy and acceptability of psychotherapies, pharmacotherapies, and their combination for the treatment of adult insomnia: A systematic review and network meta-analysis

This study aims to explore the comparative efficacy and acceptability of psychotherapies, pharmacotherapies, and their combinations for insomnia. MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, PsycINFO, CINAHL, and ClinicalTrials.gov were searched for randomized clinical trials (RCTs) examining the comparative efficacy in which a psychotherapy and a pharmacotherapy for insomnia were directly compared with each other, or in which a combination of psychotherapy and pharmacotherapy was compared with either alone. The analysis included data from 23 RCTs. In 18 of 23 studies, cognitive behavior therapy for insomnia (CBT-I) was the psychotherapy. At post-treatment, CBT-I showed higher subjective sleep efficiency (SE), and lower subjective wake time after sleep onset (WASO) and insomnia severity index (ISI) score. Compared with CBT-I plus pharmacotherapy, pharmacotherapy showed lower subjective SE, and higher subjective sleep latency (SL), PSG measured SL, subjective WASO, and ISI score. Overall, the findings derived from post-treatment data suggested that CBT-I is more beneficial in treating insomnia compared with pharmacotherapy. CBT-I combined with pharmacotherapy is beneficial in improving some sleep parameters (i.e., subjective SE, SL, WASO, and PSG measured SL) compared with pharmacotherapy alone. Daily clinical decisions should consider these findings on the relative efficacy of the principal approaches to insomnia treatment.

The orexin story, sleep and sleep disturbances

The orexins, also known as hypocretins, are two neuropeptides (orexin A and B or hypocretin 1 and 2) produced by a few thousand neurons located in the lateral hypothalamus that were independently discovered by two research groups in 1998. Those two peptides bind two receptors (orexin/hypocretin receptor 1 and receptor 2) that are widely distributed in the brain and involved in the central physiological regulation of sleep and wakefulness, orexin receptor 2 having the major role in the maintenance of arousal. They are also implicated in a multiplicity of other functions, such as reward seeking, energy balance, autonomic regulation and emotional behaviours. The destruction of orexin neurons is responsible for the sleep disorder narcolepsy with cataplexy (type 1) in humans, and a defect of orexin signalling also causes a narcoleptic phenotype in several animal species. Orexin discovery is unprecedented in the history of sleep research, and pharmacological manipulations of orexin may have multiple therapeutic applications. Several orexin receptor antagonists were recently developed as new drugs for insomnia, and orexin agonists may be the next-generation drugs for narcolepsy. Given the broad range of functions of the orexin system, these drugs might also be beneficial for treating various conditions other than sleep disorders in the near future.

Improved Functional Organization in Patients With Primary Insomnia After Individually-Targeted Transcranial Magnetic Stimulation

Primary insomnia (PI) is among the most prevalent sleep-related disorders and has a far-reaching impact on daytime functioning. Repetitive transcranial magnetic stimulation (rTMS) has drawn attention because of its effectiveness and safety. The purpose of the current study was to detect changes in the topological organization of whole-brain functional networks and to determine their associations with the clinical treatment effects of rTMS. Resting-state functional magnetic resonance imaging (rsfMRI) data from 32 patients with PI were collected and compared with findings from 32 age- and gender-matched healthy controls (HCs). The patients were treated with Stanford accelerated intelligent neuromodulation therapy, which is a recently validated neuroscience-informed accelerated intermittent theta-burst stimulation protocol. Graph theoretical analysis was used to construct functional connectivity matrices and to extract the attribute features of small-world networks in insomnia. Scores on the Insomnia Severity Index (ISI), Pittsburgh Sleep Quality Index, Self-Rating Anxiety Scale, Self-Rating Depression Scale, and the associations between these clinical characteristics and functional metrics, were the primary outcomes. At baseline, the patients with PI showed inefficient small-world property and aberrant functional segregation and functional integration compared with the HCs. These properties showed renormalization after individualized rTMS treatment. Furthermore, low functional connectivity between the right insula and left medial frontal gyrus correlated with improvement in ISI scores. We highlight functional network dysfunctions in PI patients and provide evidence into the pathophysiological mechanisms involved and the possible mode of action of rTMS.