Search Results (5)

The orexin (hypocretin) system plays a central role in regulating the sleep–wake cycle through two neuropeptides, orexin-A and orexin-B, which act on OX1R and OX2R receptors. Emerging evidence links heightened orexin signaling with the pathophysiology of chronic insomnia. This review outlines the neurobiology of the orexinergic system, compares the pharmacological profile of dual orexin receptor antagonists (DORAs) to traditional GABAergic hypnotics, and evaluates the clinical efficacy and safety of Suvorexant, Lemborexant, and Daridorexant. DORAs function by selectively dampening orexin-driven arousal, thereby facilitating sleep onset and maintenance without disrupting natural sleep architecture. Clinical trials have shown that these agents significantly reduce sleep latency and enhance sleep continuity, with a favorable side effect profile. Overall, DORAs represent a distinct and clinically advantageous option for insomnia treatment, with growing interest in their potential utility across mood, anxiety, and neurodegenerative disorders. Full article

Sleep disorders, such as insomnia and narcolepsy, significantly impact quality of life. They are often associated with long-term health consequences, including cardiovascular disease, immune dysfunction, and cognitive impairment. While traditional treatments, such as sedatives and hypnotics, can be effective, they are limited by issues of tolerance and dependence. The orexinergic system, particularly the orexin 1 receptor (OXR1), has emerged as a promising therapeutic target due to its central role in regulating sleep–wake cycles. In this study, we investigate the molecular interactions of three OXR1 antagonists—daridorexant, lemborexant, and suvorexant—using an integrated computational approach combining molecular dynamics (MD) simulations, density functional theory (DFT) calculations, and the molecular fractionation with conjugate caps (MFCC) methodology. The MFCC approach enabled the precise quantification of interaction energies between ligands and key receptor residues, providing detailed insights into the contributions of specific amino acids to binding stability. Our results reveal that residues such as GLU204, HIS216, and ASN318 play critical roles in stabilizing ligand–receptor interactions, with a marked decrease in binding energy magnitude as dielectric constants increase. Daridorexant exhibited the strongest interaction energy, driven by hydrogen bonds and hydrophobic contacts, while lemborexant and suvorexant showed distinct stabilization patterns mediated by hydrophobic interactions. These findings provide a robust molecular basis for the rational design of next-generation OXR1 antagonists with improved efficacy and safety profiles. By elucidating drug–receptor interactions at the atomic level, this research underscores the impact of integrated computational approaches in drug discovery. It supports the development of precise targeted therapies for sleep disorders. Full article

Dissolution limitations to oral absorption can occur if the time required for dissolution is longer than the transit time across the small intestine and/or if dissolution is slower than the drug’s permeation through the gut wall. These limitations most often occur for poorly soluble drugs. A standard method for overcoming dissolution issues is to reduce the particle size of the (solid) drug. Building on the refined Developability Classification System (rDCS), this work establishes a novel set of equations with which the appropriate degree of particle size reduction needed to mitigate dissolution limitations to absorption can be calculated. According to the type of data available, the appropriate equation(s) for each situation can be applied. Three case examples are used to illustrate implementation of the equations: voriconazole, lemborexant and istradefylline. Although for voriconazole (rDCS Class I) target radius (r_target) estimates indicate that particle size reduction is unnecessary, for lemborexant (rDCS Class I) a radius of ≤20 µm would be required to improve absorption. For istradefylline (rDCS Class IIb) the r_target was approximately 12 µm. Results are commensurate with literature information for these three drugs, signaling that the equations are suitable for application to a wide variety of drug substances. Full article

Lemborexant (LEM) is a novel dual orexin receptor antagonist (DORA), recently approved for the treatment of insomnia. As with other DORAs, LEM has potential of abuse and therefore placed in Schedule IV class by the United States Drug Enforcement Administration (USDEA). In this study, a sensitive and accurate UPLC-MS/MS assay was developed for the quantification of LEM in human plasma sample using losartan as an internal standard (IS). The chromatographic separation was performed by using gradient elution of mobile phase, comprising of 10 mM ammonium acetate and acetonitrile with a flow rate of 0.3 mL/min. An Acquity UPLC BEH C₁₈ (1.7 μm, 2.1 × 50 mm) column was used for separation of LEM and IS by maintaining the oven temperature of 40 °C. The electrospray ionization in positive mode was used for sample ionization. The precursor to product ion transition of 411.12 > 175.09 (qualifier) and 411.1 > 287.14 (quantifier) was used for detection and quantification of LEM, respectively, in multiple reaction monitoring mode. Being a drug of abuse, the assay was validated according to “Scientific Working Group for Toxicology” (SWGTOX) guidelines, including limit of detection (LOD), limit of quantification (LOQ), precision and bias, calibration model, interferences, carry-over effects, matrix effects, and stability parameters. The LOD and LOQ of the assay were 0.35 and 1.0 ng/mL, respectively. The linear range was between 1–300 ng/mL with correlation coefficient of ≥0.995. The method was also cross validated in rat plasma samples with acceptable ranges of precision and accuracy before its application for pharmacokinetic study in rats. Full article

Background and aim: Pancreato-biliary patients who undergo endoscopic procedures have high potential risk of delirium. Although benzodiazepine has traditionally been used to treat insomnia, this drug might increase delirium. Lemborexant may be useful for patients with insomnia, without worsening delirium, although there is no evidence for high-risk patients with pancreato-biliary disease. The aim of this pilot study was to evaluate the safety and efficacy of lemborexant for insomnia and the frequency of delirium after endoscopic procedures under deep sedation in patients with pancreato-biliary disease. Method: This retrospective study included consecutive patients who were administered lemborexant after endoscopic procedures for pancreato-biliary disease between September 2020 and June 2022. The primary outcome of this study was evaluation of the safety and efficacy of lemborexant for insomnia. Frequency of delirium was the secondary outcome. Result: In total, 64 patients who had the complication of insomnia after an endoscopic procedure were included in the study. Risk factors for delirium were advanced age (n = 36, 56.3%), dementia (n = 10, 15.6%), and regular alcohol use (n = 13, 20.3%), as well as the sedatives midazolam and pentazocine that were administered to all patients at the time of the endoscopic procedure. Successful asleep was achieved by 61/64 patients (95.3%). No fall event was observed during the night following the procedure in any patient. However, mild consciousness transformation was observed in one patient. Conclusions: In conclusion, lemborexant use may be effective and safe for use after endoscopic procedures in pancreato-biliary patients, without increasing the risk of delirium. Full article