Orexin dual receptor antagonists, zolpidem, zopiclone, eszopiclone, and cognitive research: A comprehensive dose-response 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.

The wake- and sleep-modulating neurons of the lateral hypothalamic area demonstrate a differential pattern of degeneration in Alzheimers disease

BACKGROUND

Sleep-wake dysfunction is an early and common event in Alzheimer's disease (AD). The lateral hypothalamic area (LHA) regulates the sleep and wake cycle through wake-promoting orexinergic neurons (OrxN) and sleep-promoting melanin-concentrating hormone or MCHergic neurons (MCHN). These neurons share close anatomical proximity with functional reciprocity. This study investigated LHA OrxN and MCHN loss patterns in AD individuals. Understanding the degeneration pattern of these neurons will be instrumental in designing potential therapeutics to slow down the disease progression and remediate the sleep-wake dysfunction in AD.

METHODS

Postmortem human brain tissue from donors with AD (across progressive stages) and controls were examined using unbiased stereology. Formalin-fixed, celloidin-embedded hypothalamic sections were stained with Orx-A/MCH, p-tau (CP13), and counterstained with gallocyanin. Orx or MCH-positive neurons with or without CP13 inclusions and gallocyanin-stained neurons were considered for stereology counting. Additionally, we extracted RNA from the LHA using conventional techniques. We used customized Neuropathology and Glia nCounter (Nanostring) panels to study gene expression. Wald statistical test was used to compare the groups, and the genes were considered differentially expressed when the p-value was <.05.

RESULTS

We observed a progressive decline in OrxN alongside a relative preservation of MCHN. OrxN decreased by 58% (p=0.03) by Braak stages (BB) 1-2 and further declined to 81% (p=0.03) by BB 5-6. Conversely, MCHN demonstrated a non-statistical significant decline (27%, p=0.1088) by BB 6. We observed a progressive increase in differentially expressed genes (DEGs), starting with glial profile changes in BB2. While OrxN loss was observed, Orx-related genes showed upregulation in BB 3-4 compared to BB 0-1. GO and KEGG terms related to neuroinflammatory pathways were mainly enriched.

CONCLUSIONS

To date, OrxN loss in the LHA represents the first neuronal population to die preceding the loss of LC neurons. Conversely, MCHN shows resilience to AD p-tau accumulation across Braak stages. The initial loss of OrxN correlates with specific neuroinflammation, glial profile changes, and an overexpression of HCRT, possibly due to hyperexcitation following compensation mechanisms. Interventions preventing OrxN loss and inhibiting p-tau accumulation in the LHA could prevent neuronal loss in AD and, perhaps, the progression of the disease.

Prescribing and deprescribing guidance for benzodiazepine and benzodiazepine receptor agonist use in adults with depression, anxiety, and insomnia: an international scoping review

Background

Clinical practice guidelines and guidance documents routinely offer prescribing clinicians' recommendations and instruction on the use of psychotropic drugs for mental illness. We sought to characterise parameters relevant to prescribing and deprescribing of benzodiazepine (BZD) and benzodiazepine receptor agonist (BZRA), in clinical practice guidelines and guidance documents internationally, for adult patients with unipolar depression, anxiety disorders and insomnia to understand similarities and discrepancies between evidence-based expert opinion.

Methods

A Scoping Review was conducted to characterize documents that offered evidence-based and/or consensus pharmacologic guidance on the management of unipolar depression, anxiety disorders, obsessive-compulsive disorders, post-traumatic stress disorders and insomnia. A systematic search was conducted of PubMed, SCOPUS, PsycINFO and CINAHL from inception to October 13, 2023 and supplemented by a gray literature search. Documents were screened in Covidence for eligibility. Subsequent data-charting on eligible documents collected information on aspects of both prescribing and deprescribing.

Findings

113 documents offering guidance on BZD/BZRA use were data-charted. Overall, documents gathered were from Asia (n = 11), Europe (n = 34), North America (n = 37), Oceania (n = 7), and South America (n = 4) with the remainder being "International" (n = 20) and not representative to any particular region or country. By condition the documents reviewed covered unipolar depressive disorders (n = 28), anxiety disorders, obsessive-compulsive disorder and post-traumatic stress disorder (n = 42) and Insomnia (n = 25). Few documents (n = 18) were sufficiently specific and complete to consider as de-prescribing focused documents.

Interpretation

Documents were in concordance in terms of BZD and BZRA not being used routinely as first-line pharmacologic agents. When used, it is advisable to restrict their duration to "short-term" use with the most commonly recommended duration being less than four weeks. Documents were less consistent in terms of prescriptive recommendations for specific drug, dosing and administration pattern (i.e regular or 'as needed') selection for each condition. Deprescribing documents were unanimously in favor of gradual dose reduction and patient shared decision-making. However, approaches towards dose-tapering differed substantially. Finally, there were inconsistencies and/or insufficiency of detail, among deprescribing documents, in terms of switching to a long-acting BZD, use of adjunctive pharmacotherapies and micro-tapering.

Funding

The authors received no funding for this work.

History of Psychoactive Medication a Risk Factor for Neurocognitive Decline After Cardiac Surgery

INTRODUCTION

Neurocognitive decline (NCD) is a common complication after cardiac surgery with implications for outcomes and quality of life. Identifying risk factors can help surgeons implement preventative measures, optimize modifiable risk factors, and counsel patients about risk and prognosis.

METHODS

Prospective cohort study at a single academic center. 104 patients planned to undergo cardiac surgery were enrolled. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was used to measure neurocognitive function preoperatively, on postoperative day four, and postoperative day 30. NCD is defined as a change in RBANS scaled score of < -8 from baseline to postoperative day 4. Patient charts were reviewed for medication history: beta-blockers, angiotensin-converting enzyme and angiotensin receptor blockers, calcium channel blockers, statins, oral hypoglycemic agents, and psychoactive medications. Charts were also reviewed to calculate postoperative opioid usage.

RESULTS

NCD was detected in 42.9% of patients. Incidence of NCD was significantly higher in patients taking a psychoactive medication (56.8%) than patients not (31.9%), P < 0.03. There was no relationship between historical use of beta-blocker, calcium-channel blocker, statin, or oral hypoglycemic medications and incidence of NCD. Simple linear regression showed no relationship between change in RBANS total scaled score and opioid usage. There was no difference in incidence of NCD at 1 mo.

CONCLUSIONS

Patients with a history of taking psychoactive medications prior to cardiac surgery have an increased risk of acute postoperative NCD.

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.

Orexin receptors regulate hippocampal sharp wave-ripple complexes in ex vivo slices

Orexin is a neuromodulatory peptide produced by lateral hypothalamic orexin neurons and binds to G-protein-coupled orexin-1 receptor and orexin-2 receptors. Whether orexin modulates learning and memory is not fully understood. Orexin has biphasic effects on learning and memory: promoting learning and memory at homeostatic levels and inhibiting at supra- and sub-homeostatic levels. Hippocampal sharp wave-ripples encode memory information and are essential for memory consolidation and retrieval. The role of orexin on sharp wave-ripples in hippocampal CA1 remains unknown. Here, we used multi-electrode array recordings in acute ex vivo hippocampal slices to determine the effects of orexin receptor antagonists on sharp wave-ripples. Bath-application of either the orexin-1 receptor antagonist N-(2-Methyl-6-benzoxazolyl)-N'-1,5-naphthyridin-4-yl urea (SB-334867) or the orexin-2 receptor antagonist N-Ethyl-2-[(6-methoxy-3-pyridinyl)[(2-methylphenyl)sulfonyl]amino]-N-(3-pyridinylmethyl)-acetamide (EMPA) reduced sharp wave and ripple incidence, sharp wave amplitude, and sharp wave duration. SB-334867 and EMPA effects on sharp wave amplitude and duration were equivalent, whereas EMPA exhibited a greater reduction of sharp wave and ripple incidence. EMPA also increased ripple duration, whereas SB-334867 had no effect. Inhibition of both orexin receptors with a dual orexin receptor antagonist N-[1,1'-Biphenyl]-2-yl-1-[2-[(1-methyl-1H-benzimidazol-2-yl)thio]acetyl-2-pyrrolidinedicarboxamide (TCS-1102) had effects similar to EMPA, however, sharp wave amplitude and duration were unaffected. Region-specific expression of orexin receptors suggests orexin may regulate sharp wave generation in CA3, dentate gyrus-mediated sharp wave modification, sharp wave propagation to CA1, and local ripple emergence in CA1. Our study indicates an orexin contribution to hippocampal sharp wave-ripple complexes and suggests a mechanism by which sub-homeostatic concentrations of orexin may inhibit learning and memory function.