Residual effects of low dose of suvorexant, zolpidem, and ramelteon in healthy elderly subjects: A randomized double‐blind study

Short-Term Efficacy and Safety of Suvorexant and Lemborexant: A Retrospective Study

PURPOSE

Given the risks of long-term benzodiazepine use, safer alternatives like orexin receptor antagonists (ORAs) are needed for insomnia treatment. This study aims to compare suvorexant and lemborexant, focusing on early-stage sleep duration as an efficacy measure and fall incidence as a safety measure.

METHODS

We included patients admitted to our hospital between April 1, 2022 and December 31, 2022, who were newly prescribed suvorexant or lemborexant, excluding patients taking other concomitant sleep medications or antipsychotics. Primary and secondary endpoints were sleep duration during the first three days after taking the medications and the incidence of falls, respectively.

RESULTS

We analyzed data from 48 and 57 patients taking suvorexant and lemborexant, respectively. When compared with that in the pre-treatment period, sleep duration was significantly longer on days 2 and 3 in the suvorexant group, and on all three days in the lemborexant group. On day 1 of drug administration, the lemborexant group had a significantly longer sleep duration than the suvorexant group (5.10 ± 1.84 vs. 5.93 ± 1.90 h, respectively; P = 0.017). Zero (0.0%) and three (5.3%) falls occurred in the suvorexant and lemborexant groups, respectively (P = 0.248).

CONCLUSIONS

Lemborexant exerted a potent inhibitory effect on orexin 2 receptors, which could explain the longer sleep duration experienced by patients taking this drug on the first day of treatment.

Evaluation of sunobinop for next-day residual effects in healthy participants

Sunobinop is a novel, potent, selective partial agonist at nociceptin/orphanin FQ peptide (NOP) receptors. The primary objective of this randomized, double-blind, placebo-controlled study was to assess the next-day residual effects of an evening dose of sunobinop in healthy participants. Participants were randomized into 1 of 5 treatment sequences. Treatment consisted of 1 dose each of sunobinop 0.2, 0.6, 2, and 6 mg suspension and placebo suspension. Key pharmacodynamic (PD) measures included the digit symbol substitution test (DSST), Karolinska sleepiness scale (KSS), and body sway. The randomized safety population consisted of 25 participants. The DSST, KSS, and body sway showed dose-dependent effects following the administration of sunobinop, with no significant differences versus placebo at sunobinop doses <2 mg. At sunobinop 2 mg, PD effects were relatively small in magnitude and inconsistent. The last timepoint where significant differences between sunobinop 2 mg and placebo on the DSST, KSS, and body sway were observed was at 12 h, 16.5 h, and 13.5 h postdose, respectively. Sunobinop 6 mg resulted in larger and consistent PD effects, with significant differences from placebo at all timepoints up to 16.5-18 h postdose. Somnolence was the most frequently reported adverse event (AE), and all AEs were mild-to-moderate. No deaths occurred during the study or discontinuations due to an AE. Overall, a nighttime oral dose of sunobinop up to 2 mg was safe and generally well tolerated in healthy participants with limited next-day residual effects that were consistent with other sedative/hypnotic drugs.

Preventive Effects of Ramelteon, Suvorexant, and Lemborexant on Delirium in Hospitalized Patients With Physical Disease: A Retrospective Cohort Study

BACKGROUND

New sleep-inducing drugs (eg, ramelteon, suvorexant, and lemborexant) have been shown to prevent delirium in high-risk groups. However, no single study has simultaneously evaluated the delirium-preventing effects of all novel sleep-inducing drugs in hospitalized patients. Therefore, this study aimed to clarify the relationship between sleep-inducing drugs and delirium prevention in patients hospitalized in general medical-surgical settings for nonpsychiatric conditions who underwent liaison interventions for insomnia.

METHODS

This retrospective cohort study included patients treated in general medical-surgical settings for nonpsychiatric conditions with consultation-liaison psychiatry consult for insomnia. Delirium was diagnosed by fully certified psychiatrists using the Diagnostic and Statistical Manual of Mental Disorders 5 th edition. The following items were retrospectively examined from medical records as factors related to delirium development: type of sleep-inducing drugs, age, sex, and delirium risk factors. The risk factors of delirium development were calculated using adjusted odds ratios (aORs) via multivariate logistic regression analysis.

RESULTS

Among the 710 patients analyzed, 257 (36.2%) developed delirium. Suvorexant (aOR, 0.61; 95% confidence interval [CI], 0.40-0.94; P = 0.02) and lemborexant (aOR, 0.23; 95% CI, 0.14-0.39; P < 0.0001) significantly reduced the risk of developing delirium. Benzodiazepines (aOR, 1.90; 95% CI, 1.15-3.13; P = 0.01) significantly increased this risk. Ramelteon (aOR, 1.30; 95% CI, 0.84-2.01; P = 0.24) and Z-drugs (aOR, 1.27; 95% CI, 0.81-1.98; P = 0.30) were not significantly associated with delirium development.

CONCLUSIONS

The use of suvorexant and lemborexant may prevent delirium in patients with a wide range of medical conditions.

Efficacy and Safety of Transitioning to Lemborexant from Z-drug, Suvorexant, and Ramelteon in Japanese Insomnia Patients: An Open-label, Multicenter Study

INTRODUCTION

For patients with chronic insomnia, conventional therapy may not always provide satisfactory efficacy and safety. Thus, switching to an alternative therapeutic agent can be explored. However, there is a lack of prospective studies evaluating the effectiveness of such changes. This prospective, non-randomized, open-label, interventional, multicenter study assessed whether Japanese patients with chronic insomnia dissatisfied with treatment could transition directly to lemborexant (LEM) from four cohorts-non-benzodiazepine sedative-hypnotic (zolpidem, zopiclone, or eszopiclone) monotherapy, dual orexin receptor antagonist (suvorexant) monotherapy, suvorexant + benzodiazepine receptor agonists (BZRAs), and melatonin receptor agonist (ramelteon) combination. We evaluated whether transitioning to LEM improved patient satisfaction based on efficacy and safety.

METHODS

The primary endpoint was the proportion of successful transitions to LEM at 2 weeks (titration phase end), defined as the proportion of patients on LEM by the end of the 2-week titration phase who were willing to continue on LEM during the maintenance phase (Weeks 2-14). Patient satisfaction and safety (the incidence of treatment-emergent adverse events [TEAEs]) were assessed at 14 weeks (end of titration and maintenance phases).

RESULTS

Among the 90 patients enrolled, 95.6% (95% confidence interval: 89.0-98.8%) successfully transitioned to LEM at 2 weeks. The proportions of patients who successfully continued on LEM were 97.8% and 82.2% at the end of the titration and maintenance phases (Weeks 2 and 14), respectively. The overall incidence of TEAEs was 47.8%; no serious TEAEs occurred. In all cohorts, the proportions of patients with positive responses were higher than the proportions with negative responses on the three scales of the Patient Global Impression-Insomnia version. During the maintenance phase, Insomnia Severity Index scores generally improved at Weeks 2, 6, and 14 of LEM transition.

CONCLUSIONS

Direct transition to LEM may be a valid treatment option for patients with insomnia who are dissatisfied with current treatment.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT04742699.

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.

Suvorexant Acutely Decreases Tau Phosphorylation and Aβ in the Human CNS

OBJECTIVE

In Alzheimer's disease, hyperphosphorylated tau is associated with formation of insoluble paired helical filaments that aggregate as neurofibrillary tau tangles and are associated with neuronal loss and cognitive symptoms. Dual orexin receptor antagonists decrease soluble amyloid-β levels and amyloid plaques in mouse models overexpressing amyloid-β, but have not been reported to affect tau phosphorylation. In this randomized controlled trial, we tested the acute effect of suvorexant, a dual orexin receptor antagonist, on amyloid-β, tau, and phospho-tau.

METHODS

Thirty-eight cognitively unimpaired participants aged 45 to 65 years were randomized to placebo (N = 13), suvorexant 10 mg (N = 13), and suvorexant 20 mg (N = 12). Six milliliters of cerebrospinal fluid were collected via an indwelling lumbar catheter every 2 hours for 36 hours starting at 20:00. Participants received placebo or suvorexant at 21:00. All samples were processed and measured for multiple forms of amyloid-β, tau, and phospho-tau via immunoprecipitation and liquid chromatography-mass spectrometry.

RESULTS

The ratio of phosphorylated-tau-threonine-181 to unphosphorylated-tau-threonine-181, a measure of phosphorylation at this tau phosphosite, decreased ~10% to 15% in participants treated with suvorexant 20 mg compared to placebo. However, phosphorylation at tau-serine-202 and tau-threonine-217 were not decreased by suvorexant. Suvorexant decreased amyloid-β ~10% to 20% compared to placebo starting 5 hours after drug administration.

INTERPRETATION

In this study, suvorexant acutely decreased tau phosphorylation and amyloid-β concentrations in the central nervous system. Suvorexant is approved by the US Food and Drug Administration to treatment insomnia and may have potential as a repurposed drug for the prevention of Alzheimer's disease, however, future studies with chronic treatment are needed. ANN NEUROL 2023;94:27-40.

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.