Alertness and psychomotor performance effects of the histamine-3 inverse agonist MK-0249 in obstructive sleep apnea patients on continuous positive airway pressure therapy with excessive daytime sleepiness: a randomized adaptive crossover study

Evaluating pharmacological treatments for excessive daytime sleepiness in obstructive sleep apnea: A comprehensive network meta-analysis and systematic review

Obstructive sleep apnea (OSA) is associated with excessive daytime sleepiness (EDS). Pharmacotherapy offers a potential treatment approach for EDS in OSA patients. This systematic review and meta-analysis aimed to assess the efficacy and safety of pharmacological interventions for alleviating EDS in patients with OSA. Following PRISMA guidelines, we included randomized controlled trials investigating pharmacological treatments for EDS in adult OSA until August 2023. We conducted meta-analysis, subgroup, and meta-regression analyses using a random effects model. Finally, a network meta-analysis synthesized direct and indirect evidence, followed by a comprehensive safety analysis. We included 32 articles in the meta-analysis (n = 3357). Pharmacotherapy showed a significant improvement in the Epworth Sleepiness Scale (ESS) score (Mean Difference (MD) -2.73, (95 % Confidence Interval (CI) [-3.25, -2.20], p < 0.01) and Maintenance of Wakefulness Test (MWT) score (MD 6.00 (95 % CI [2.66, 9.33] p < 0.01). Solriamfetol, followed by Pitolisant and modafinil, exhibited the greatest ESS reduction, while Danavorexton, followed by Solriamfetol and MK-7288, had the strongest impact on MWT. MK-7288 had the most total adverse events (AEs), followed by Danavorexton and armodafinil. Pharmacological Interventions significantly alleviate EDS in OSA patients but with heterogeneity across medications. Treatment decisions should involve a personalized assessment of patient factors and desired outcomes.

Effects of new hypnotic drugs on cognition: A systematic review and network meta-analysis

Background

Insomnia is a common disease, and the application of various types of sleeping pills for cognitive impairment is controversial, especially as different doses can lead to different effects. Therefore, it is necessary to evaluate the cognitive impairment caused by different sleeping pills to provide a theoretical basis for guiding clinicians in the selection of medication regimens.

Objective

To evaluate whether various different doses (low, medium and high) of anti-insomnia drugs, such as the dual-orexin receptor antagonist (DORA), zopiclone, eszopiclone and zolpidem, induce cognitive impairment.

Methods

The PubMed, Embase, Scopus, Cochrane Library, and Google Scholar databases were searched from inception to September 20th, 2022 for keywords in randomized controlled trials (RCTs) to evaluate the therapeutic effects of DORA, eszopiclone, zopiclone and zolpidem on sleep and cognitive function. The primary outcomes were indicators related to cognitive characteristics, including scores on the Digit Symbol Substitution Test (DSST) and daytime alertness. The secondary outcomes were the indicators associated with sleep and adverse events. Continuous variables were expressed as the standard mean difference (SMD). Data were obtained through GetData 2.26 and analyzed by Stata v.15.0.

Results

A total of 8702 subjects were included in 29 studies. Eszopiclonehigh significantly increased the daytime alertness score (SMD = 3.00, 95 % CI: 1.86 to 4.13) compared with the placebo, and eszopiclonehigh significantly increased the daytime alertness score (SMD = 4.21, 95 % CI: 1.65 to 6.77; SMD = 3.95, 95 % CI: 1.38 to 6.51; SMD = 3.26, 95 % CI: 0.38 to 6.15; and SMD = 3.23, 95 % CI: 0.34 to 6.11) compared with zolpidemlow, zolpidemhigh, DORAlow, and eszopiclonemid, respectively. Compared with the placebo, zopiclone, zolpidemmid, and eszopiclonehigh, DORA significantly increased the TST (SMD = 2.39, 95 % CI: 1.11 to 3.67; SMD = 6.00, 95 % CI: 2.73 to 9.27; SMD = 1.89, 95 % CI: 0.90 to 2.88; and SMD = 1.70, 95 % CI: 0.42 to 2.99, respectively).

Conclusion

We recommend DORA as the best intervention for insomnia because it was highly effective in inducing and maintaining sleep without impairing cognition. Although zolpidem had a more pronounced effect on sleep maintenance, this drug is better for short-term use. Eszopiclone and zopiclone improved sleep, but their cognitive effects have yet to be verified.

Comparative Efficacy and Safety of Wakefulness-Promoting Agents for Excessive Daytime Sleepiness in Patients With Obstructive Sleep Apnea : A Systematic Review and Network Meta-analysis

BACKGROUND

Excessive daytime sleepiness (EDS) is common among patients with obstructive sleep apnea (OSA). The comparative effectiveness of pharmacologic agents is unknown.

PURPOSE

To compare the effectiveness of drugs for EDS in OSA using network meta-analysis.

DATA SOURCES

MEDLINE, CENTRAL, EMBASE, and ClinicalTrials.gov to 7 November 2022.

STUDY SELECTION

Reviewers identified randomized trials that enrolled patients with EDS-associated OSA on or eligible for conventional therapy assigned to any pharmacologic intervention.

DATA EXTRACTION

Paired reviewers independently extracted data addressing effects of drugs on the Epworth Sleepiness Scale (ESS), Maintenance of Wakefulness Test (MWT), and adverse events at the longest reported follow-up. The certainty of evidence was assessed using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach.

DATA SYNTHESIS

Fourteen trials (3085 patients) were eligible. At 4 weeks, compared with placebo, solriamfetol improves ESS scores (mean difference [MD], -3.85 [95% CI, -5.24 to -2.50]; high certainty), and armodafinil-modafinil (MD, -2.25 [CI, -2.85 to -1.64]; moderate certainty) and pitolisant-H3-autoreceptor blockers (MD, -2.78 [CI, -4.03 to -1.51]; moderate certainty) probably improve ESS scores. At 4 weeks, compared with placebo, solriamfetol (standardized mean difference [SMD], 0.9 [CI, 0.64 to 1.17]) and armodafinil-modafinil (SMD, 0.41 [CI, 0.27 to 0.55]) improve MWT (both high certainty), whereas pitolisant-H3-autoreceptor blockers probably do not (moderate certainty). At 4 weeks, armodafinil-modafinil probably increases the risk for discontinuation due to adverse events (relative risk [RR], 2.01 [CI, 1.14 to 3.51]; moderate certainty); solriamfetol may increase the risk for discontinuation due to adverse events (RR, 2.07 [CI, 0.67 to 6.25]; low certainty). Low certainty evidence suggests these interventions may not increase the risk for serious adverse events.

LIMITATIONS

There is limited evidence on long term or effectiveness among patients nonadherent or with mixed adherence to conventional OSA therapies.

CONCLUSION

Solriamfetol, armodafinil-modafinil, and pitolisant reduce daytime sleepiness for patients with OSA already on conventional therapy, with solriamfetol likely superior. Adverse events probably increase the risk for discontinuation of armodafinil-modafinil and may increase the risk for discontinuation with solriamfetol.

PRIMARY FUNDING SOURCE

None.

Placebo response in objective and subjective measures of hypersomnia in randomized clinical trials on obstructive sleep apnea. A systematic review and meta-analysis

Sleepiness is one of the outcomes most used in randomized clinical trials (RCT) on the effect of treatments for obstructive sleep apnea (OSA). Furthermore, it is known that there is a placebo effect, especially in subjective measures. Therefore, given that sleepiness is a subjective measure, the objective of this systematic review with meta-analysis and three-level meta-regression was to assess the response to different placebos (pills and sham-CPAP) used in RCTs in OSA, both on subjective (Epworth Sleepiness Scale [ESS]) and objective (Multiple Sleep Latency Test [MSLT], Maintenance Wake Test [MWT], the Osler test and the Psychomotor Vigilance Task [PVT]). We observed a statistically significant placebo effect in both subjective and objective measures of hypersomnia, and in both sham-CPAP and pills. This placebo effect was greater, even clinically significant, in subjective measures (ESS: -2.84 points) and in those RCTs that used pills as a placebo. In the meta-regression, only a higher baseline value of the ESS and Osler test was related to the placebo effect.

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

Background

About one-third of adults have trouble sleeping, ranging from occasional difficulty to chronic insomnia, along with difficulty maintaining sleep. Many studies reported that the long-term use of hypnotics can cause brain dysfunction and damage cognition.

Objective

The objective of the study is to evaluate whether low, medium, and high doses of orexin dual receptor antagonists (DORA), zopiclone (ZOP), eszopiclone (ESZ), and zolpidem (ZST) can impair cognition.

Methods

From the beginning through September 20, 2022, PubMed, Embase, Scopus, the Cochrane Library, and Google Scholar were searched. Randomized controlled trials (RCTs) assessing the therapeutic effects of DORA, eszopiclone, and zopiclone for sleep and cognitive function were included. The primary outcomes were indices related to the cognitive profile, including memory, alertness, execution and control function, and attention and orientation. The secondary outcomes were indices related to sleep and adverse events. The standard mean difference (SMD) was generated for continuous variables. Certain data were captured from figures by GetData 2.26 and analyzed using RStudio 4.2.

Results

Finally, a total of 8,702 subjects were included in 29 studies. Compared with the placebo, the DSST (Digit Symbol Substitution Test) scores of low, medium, and high doses of DORA were SMD = 0.77; 95% CI: 0.33-1.20; SMD = 1.58; 95% CI: 1.11-2.05; and SMD = 0.85; 95% CI: 0.33-1.36, respectively. The DSST scores of zolpidem at low, medium, and high doses were SMD = -0.39; 95% CI: 0.85-0.07; SMD = -0.88, 95% CI: -2.34-0.58; and SMD = -0.12, 95% CI: -0.85-0.60, respectively. Zopiclone's DSST scale score was SMD = -0.18; 95% CI: -0.54-0.18. In addition, the total sleep time (TST) of low, medium, and high doses of DORA was SMD = 0.28, 95% CI: -0.15-0.70; SMD = 1.36, 95% CI: 0.87-1.86; and SMD = 2.59, 95% CI: 1.89-3.30, respectively. The TST of zolpidem with low, medium, and high doses was SMD = 1.01, 95% CI: 0.18-1.83; SMD = 1.94, 95% CI: 0.46-3.43; and SMD = 1.71, 95% CI: 0.86-2.56, respectively. The TST of low, medium, and high doses of eszopiclone was relatively SMD = 2.03, 95% CI: -0.21-4.27; SMD = 2.38, 95% CI: 1.35-3.42; and SMD = 1.71, 95% CI: 0.60-2.82. Zopiclone's TST was SMD = 2.47, 95% CI: 1.36-3.58.

Conclusion

We recommend DORA as the best intervention for insomnia because it is highly effective in inducing and maintaining sleep without impairing cognition. Although zolpidem has a more pronounced effect on maintaining sleep, it is best to reduce its use because of its side effects. Eszopiclone and zopiclone improved sleep quality, but their safety in cognition remains to be verified.

Samelisant (SUVN-G3031), a potent, selective and orally active histamine H3 receptor inverse agonist for the potential treatment of narcolepsy: pharmacological and neurochemical characterisation

RATIONALE

Samelisant (SUVN-G3031) is a potent and selective histamine H3 receptor (H3R) inverse agonist with good brain penetration and oral bioavailability.

OBJECTIVES

Pharmacological and neurochemical characterisation to support the utility of Samelisant (SUVN-G3031) in the treatment of sleep-related disorders like narcolepsy.

METHODS

Samelisant (SUVN-G3031) was tested in rat brain microdialysis studies for evaluation of modulation in histamine, dopamine and norepinephrine. Sleep EEG studies were carried out in orexin knockout mice to study the effects of Samelisant (SUVN-G3031) on the sleep-wake cycle and cataplexy.

RESULTS

Samelisant (SUVN-G3031) has a similar binding affinity towards human (hH3R; K_i = 8.7 nM) and rat (rH3R; K_i = 9.8 nM) H3R indicating no inter-species differences. Samelisant (SUVN-G3031) displays inverse agonist activity and it exhibits very high selectivity towards H3R. Samelisant (SUVN-G3031) treatment in mice produced a dose-dependent increase in tele-methylhistamine levels indicating the activation of histaminergic neurotransmission. Apart from increasing the levels of histamine, Samelisant (SUVN-G3031) also modulates dopamine and norepinephrine levels in the cerebral cortex while it has no effects on dopamine levels in the striatum or nucleus accumbens. Treatment with Samelisant (SUVN-G3031; 10 and 30 mg/kg, p.o.) produced a significant increase in wakefulness with a concomitant decrease in NREM sleep in orexin knockout mice subjected to sleep EEG. Samelisant (SUVN-G3031) also produced a significant decrease in Direct REM sleep onset (DREM) episodes, demonstrating its anticataplectic effects in an animal model relevant to narcolepsy. Modulation in cortical levels of histamine, norepinephrine and dopamine provides the neurochemical basis for wake-promoting and anticataplectic effects observed in orexin knockout mice.

CONCLUSIONS

Pre-clinical studies of Samelisant (SUVN-G3031) provide a strong support for utility in the treatment of sleep-related disorders related to EDS and is currently being evaluated in a phase 2 proof of concept study in the USA for the treatment of narcolepsy with and without cataplexy.

Diagnostik und Therapie der residualen Tagesschläfrigkeit bei Patienten mit therapierter obstruktiver Schlafapnoe

Die residuale Tagesschläfrigkeit tritt bei 12–65 % der Schlafapnoe-Patienten unter eingeleiteter Positivdrucktherapie („positive airway pressure“) auf. Eine häufige Ursache ist die geringe PAP-Nutzungszeit. Mögliche weitere Gründe sind ein hoher Rest-Apnoe-Hypopnoe-Index und eine vorhandene Komorbidität. Prädiktoren sind ein initial hoher Epworth-Schläfrigkeitsscore, jüngeres Alter und die erst kurze PAP-Nutzung. Gesichert wird die Restschläfrigkeit mittels objektiver Testverfahren (z. B. multipler Wachbleibetest oder Oxford Sleep Resistance Test [Osler-Test]). Eine der wesentlichen Ursachen für die residuale Schläfrigkeit nach Ausschluss konkurrierender Auslöser ist die stattgehabte intermittierende nächtliche Hypoxämie, die zu nervalen Zellschädigungen, zu hormonellen und genetischen Veränderungen und zu Änderungen des Mikrobioms führen kann.

Die klinischen Beschwerden werden bestimmt durch eine ausgeprägte Tagesschläfrigkeit, depressive Verstimmung und eine Minderung der Lebensqualität.

Nach Ausschluss möglicher therapiebedingter Ursachen kann die residuale Tagesschläfrigkeit medikamentös mit u. a. Modafinil, Armodafinil, Pitolisant oder Solriamfetol behandelt werden. Die genannten Arzneimittel haben unterschiedliche Wirkmechanismen. Die Studien und die Effekte der Substanzen auf die Tagesschläfrigkeit, die Lebensqualität und die Leistungsfähigkeit der Betroffenen werden vorgestellt. Das Nebenwirkungsprofil der Wirkstoffe ist ähnlich. Für die Indikation residuale Schläfrigkeit einer therapierten obstruktiven Schlafapnoe ist in Europa derzeit nur Solriamfetol zugelassen.

Ein vom Autorenteam entworfener Behandlungspfad für Patienten mit therapierter obstruktiver Schlafapnoe mit residualer Tagesschläfrigkeit, von der Erstvorstellung nach Therapiebeginn über die Therapieoptimierung bis hin zu einer medikamentösen Behandlung, wird vorgestellt.

Futility stopping in clinical trials, optimality and practical considerations

Stopping for futility is a useful tool in a clinical trial. It is widely used in single-arm trials in oncology and in many two-arm trials. We review three stopping rules for futility. We give recommendations for the optimal timing of futility looks in two-stage trials in terms of the information fraction and the probability of stopping under the alternative hypothesis. We discuss futility stopping in trials with substantial uncertainty about the variability of the outcome and in crossover trials.

Progress in the development of histamine H3 receptor antagonists/inverse agonists: a patent review (2013-2017)

INTRODUCTION

Since years, ligands blocking histamine H₃ receptor (H₃R) activity (antagonists/inverse agonists) are interesting targets in the search for new cures for CNS disorders. Intensive works done by academic and pharmaceutical company researchers have led to many potent and selective H₃R antagonists/inverse agonists. Some of them have reached to clinical trials.

AREAS COVERED

Patent applications from January 2013 to September 2017 and the most important topics connected with H₃R field are analysed. Espacenet, Patentscope, Pubmed, GoogleScholar or Cochrane Library online databases were principially used to collect all the materials.

EXPERT OPINION

The research interest in histamine H₃R field is still high although the number of patent applications has decreased during the past 4 years (around 20 publications). Complexity of histamine H₃R biology e.g. many isoforms, constitutive activity, heteromerization with other receptors (dopamine D₂, D₁, adenosine A_2A) and pharmacology make not easy realization and evaluation of therapeutic potential of anti-H₃R ligands. First results from clinical trials have verified potential utility of histamine H₃R antagonist/inverse agonists in some diseases. However, more studies are necessary for better understanding of an involvement of the histaminergic system in CNS-related disorders and helping more ligands approach to clinical trials and the market. Lists of abbreviations: hAChEI - human acetylcholinesterase inhibitor; hBuChEI - human butyrylcholinesterase inhibitor; hMAO - human monoamine oxidase; MAO - monoamine oxidase.

International Union of Basic and Clinical Pharmacology. XCVIII. Histamine Receptors

Histamine is a developmentally highly conserved autacoid found in most vertebrate tissues. Its physiological functions are mediated by four 7-transmembrane G protein-coupled receptors (H1R, H2R, H3R, H4R) that are all targets of pharmacological intervention. The receptors display molecular heterogeneity and constitutive activity. H1R antagonists are long known antiallergic and sedating drugs, whereas the H2R was identified in the 1970s and led to the development of H2R-antagonists that revolutionized stomach ulcer treatment. The crystal structure of ligand-bound H1R has rendered it possible to design new ligands with novel properties. The H3R is an autoreceptor and heteroreceptor providing negative feedback on histaminergic and inhibition on other neurons. A block of these actions promotes waking. The H4R occurs on immuncompetent cells and the development of anti-inflammatory drugs is anticipated.

Modafinil/armodafinil in obstructive sleep apnoea: a systematic review and meta-analysis

Modafinil is used internationally to treat residual sleepiness despite continuous positive airway pressure in obstructive sleep apnoea (res-OSA). In 2011, the European Medicines Agency removed the indication based on an unfavourable risk–benefit profile in two trials for efficacy and all accumulated safety data. We performed a meta-analysis of all randomised controlled trials of modafinil (or armodafinil) in res-OSA to quantify efficacy and safety.

We systematically searched and assessed studies from major databases, conferences and trials registries to find randomised, placebo-controlled trials of modafinil/armodafinil for ≥2 weeks in adult res-OSA treating sleepiness.

We analysed 10 of the 232 articles identified that met inclusion criteria (1466 patients). Modafinil/armodafinil improved the Epworth Sleepiness Scale score (2.2 points, 95% CI 1.5–2.9) and the Maintenance of Wakefulness Test over placebo (3 min, 95% CI 2.1–3.8 min). Modafinil/armodafinil tripled adverse events and doubled adverse events leading to withdrawal but did not increase serious adverse events (hospitalisations or death).

Modafinil and armodafinil improve subjective and objective daytime sleepiness in res-OSA. We believe our analysis is a fairer analysis of the risk–benefit profile of this indication. Clinicians may want to use this data to balance the risks and benefits on a case-by-case basis with their patients.

Acid-sensing hypothalamic neurons controlling arousal

Breathing and vigilance are regulated by pH and CO2 levels in the central nervous system. The hypocretin/orexin (Hcrt/Orx)- and histamine (HA)-containing hypothalamic neurons synergistically control different aspects of the waking state. Acidification inhibits firing of most neurons but these two groups in the caudal hypothalamus are excited by hypercapnia and protons, similar to the chemosensory neurons in the brain stem. Activation of hypothalamic wake-on neurons in response to hypercapnia, seen with the c-Fos assay, is supported by patch-clamp recordings in rodent brain slices: Hcrt/Orx and HA neurons are excited by acidification in the physiological range (pH from 7.4 to 7.0). Multiple molecular mechanisms mediate wake-promoting effects of protons in HA neurons in the tuberomamillary nucleus (TMN): among them are acid-sensing ion channels, Na(+),K(+)-ATPase, group I metabotropic glutamate receptors (mGluRI). HA neurons are remarkably sensitive to the mGluRI agonist DHPG (threshold concentration 0.5 µM) and mGluRI antagonists abolish proton-induced excitation of HA neurons. Hcrt/Orx neurons are excited through block of a potassium conductance and release glutamate with their peptides in TMN. The two hypothalamic nuclei and the serotonergic dorsal raphe cooperate toward CO2/acid-induced arousal. Their interactions and molecular mechanisms of H(+)/CO2-induced activation are relevant for the understanding and treatment of respiratory and metabolic disorders related to sleep-waking such as obstructive sleep apnea and sudden infant death syndrome.