Population and Noncompartmental Pharmacokinetics of Sodium Oxybate Support Weight‐Based Dosing in Children and Adolescents With Narcolepsy With Cataplexy

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Implications of Oxybate Dosing Regimen for Sleep, Sleep Architecture, and Disrupted Nighttime Sleep in Patients with Narcolepsy: A Commentary

Abstract Narcolepsy is associated with disrupted nighttime sleep (DNS). Sodium oxybate (SXB; Xyrem®), administered twice nightly, is indicated for the treatment of cataplexy and excessive daytime sleepiness in patients 7 years or older with narcolepsy. Recently, low-sodium oxybate (LXB, Xywav®; for people 7 years of age and older), which contains 92% less sodium than SXB and is dosed twice nightly, and sodium oxybate for extended release (SXB-ER; Lumryz™; for adults), which contains equal sodium to SXB and is dosed once nightly, have also been approved to treat cataplexy or excessive daytime sleepiness in narcolepsy. This paper reviews the evidence regarding the overall impact of oxybate administration, and impact of different oxybate dosing regimens (once nightly, SXB-ER; twice nightly, SXB), on DNS in narcolepsy utilizing polysomnographic data from five clinical trials (three assessing SXB in adults [referred to here as SXB trials 1, 2, and 3], one assessing SXB in children [referred to as the pediatric SXB trial], and one assessing SXB-ER in adults [REST-ON]). Both once-nightly and twice-nightly oxybate regimens similarly improved symptoms of DNS. Regardless of dosing regimen, people with narcolepsy treated with oxybate experience roughly 42–53 arousals and 9–38 awakenings each night, with one of these awakenings on twice-nightly oxybate being due to the second dosing requirement in studies of SXB. Additionally, for SXB, but not SXB-ER, polysomnographic data has been analyzed by half of the night, demonstrating a greater positive impact on sleep architecture in the second half of the night, which might be related to its nonlinear pharmacokinetic profile. We conclude that while once-nightly and twice-nightly oxybate dosing regimens differ in their pharmacokinetic profiles, both improve DNS in patients with narcolepsy to a similar degree

Recommended protocols for the Multiple Sleep Latency Test and Maintenance of Wakefulness Test in adults: guidance from the American Academy of Sleep Medicine.

This article updates the American Academy of Sleep Medicine protocols for the administration of the Multiple Sleep Latency Test and the Maintenance of Wakefulness Test. The American Academy of Sleep Medicine commissioned a task force of clinical experts in sleep medicine to review published literature on the performance of these tests since the publication of the 2005 American Academy of Sleep Medicine practice parameter paper. Although no evidence-based changes to the protocols were warranted, the task force made several changes based on consensus. These changes included guidance on patient preparation, medication and substance use, sleep before testing, test scheduling, optimum test conditions, and documentation. This article provides guidance to providers who order and administer the Multiple Sleep Latency Test and the Maintenance of Wakefulness Test.CitationKrahn LE, Arand DL, Avidan AY, et al. Recommended protocols for the Multiple Sleep Latency Test and the Maintenance of Wakefulness Test in adults: guidance from the American Academy of Sleep Medicine. J Clin Sleep Med. 2021;17(12):2489-2498

Treatment of paediatric narcolepsy with sodium oxybate: a double-blind, placebo-controlled, randomised-withdrawal multicentre study and open-label investigation

Background: Narcolepsy is a lifelong neurological disorder with onset commonly in childhood or adolescence. No drugs are indicated for cataplexy and excessive daytime sleepiness in paediatric patients with narcolepsy. Sodium oxybate is approved for use in adult patients with excessive daytime sleepiness or cataplexy, or both, in narcolepsy. We aimed to examine the safety and efficacy of sodium oxybate oral solution treatment in children and adolescents who have narcolepsy with cataplexy. Methods: This was a prospective, double-blind, placebo-controlled, randomised-withdrawal, multisite study and open-label investigation done at 30 sites in five countries (USA, Finland, France, Italy, and the Netherlands). Eligible participants were aged 7\u201316 years at screening, had narcolepsy with cataplexy, and were either being treated with sodium oxybate or were sodium oxybate-naive at entry. Sodium oxybate-naive participants were titrated to an optimal dose. Participants were randomly assigned (1:1) with a dynamic randomisation algorithm to receive placebo or to remain on sodium oxybate for 2 weeks; they then entered an open-label sodium oxybate treatment period for a total study duration of up to 1 year. Random assignment to placebo was discontinued if early efficacy was shown in the preplanned interim analysis of the primary efficacy endpoint, which was change in weekly number of cataplexy attacks. Participants entering the study after the interim analysis would then be assigned to receive open-label sodium oxybate for 2 weeks. The primary analysis of efficacy and safety included data collected until the cutoff date of Feb 10, 2017. The efficacy population consisted of all participants randomly assigned to receive an intervention who completed at least 5 days of dosing in the double-blind treatment period, and the safety population consisted of all participants who took the study drug, including open-label sodium oxybate. This study is registered with ClinicalTrials.gov, number NCT02221869. Findings: Between Oct 1, 2014, and Feb 10, 2017, we enrolled 106 participants, and 104 took the study drug (the safety population). 96 (92%) of these participants completed the stable-dose period, of whom 63 participants (the efficacy population) were randomly assigned to receive sodium oxybate (n=31) or placebo (n=32) for 2 weeks. A preplanned interim analysis of the primary endpoint showed efficacy (p=0\ub70002), resulting in discontinuation of the placebo arm following guidance from the data safety monitoring board; 33 participants then received sodium oxybate on an open-label basis during the double-blind period. Participants who were randomly assigned to receive placebo and who were withdrawn from sodium oxybate (32 [51%] of 63 patients) had increased weekly cataplexy attacks (median increase of 12\ub77 attacks per week [Q1, Q3=3\ub74, 19\ub78]) when compared with those randomly assigned to continue treatment with sodium oxybate (median increase of 0\ub73 attacks per week [\u20131\ub70, 2\ub75]; p5%) adverse events were enuresis (15 [21%] of 72 sodium oxybate-naive participants vs four [13%] of 32 participants taking sodium oxybate at study entry), nausea (16 [22%] vs two [6%]), vomiting (15 [21%] vs two [6%]), headache (13 [18%] vs four [13%]), decreased weight (11 [15%] vs one [3%]), decreased appetite (eight [11%] vs none), nasopharyngitis (seven [10%] vs none), and dizziness (five [7%] vs 1 [3%]). Two serious adverse events (one event of severe acute psychosis and one event of moderate suicidal ideation) were reported, and both were considered to be related to the study drug. There were no reported deaths. Interpretation: These results support the clinical efficacy of sodium oxybate for the treatment of both excessive daytime sleepiness and cataplexy in narcolepsy in children. The safety profile of sodium oxybate was consistent with that observed in adult patients. Funding: Jazz Pharmaceuticals

Five-Minute Awake Snoring Test for Determining CPAP Pressures (Five-Minute CPAP Test): A Pilot Study

Objective. To develop a quick, simple, bedside test for determining continuous positive airway pressures (CPAP) for obstructive sleep apnea (OSA) patients. Study Design. Prospective case series at a tertiary medical center. Methods. The Five-Minute Awake Snoring Test for Determining CPAP (Five-Minute CPAP Test) was developed and tested. Patients wear a soft-gel nasal triangle mask while holding a tongue depressor with the wide section (1.75 cm) between the teeth. Fixed pressure nasal CPAP is applied while the patient simulates snoring at 4 centimeters of water pressure. The pressure is incrementally titrated up and then down to determine the lowest pressure at which the patient cannot snore (Quiet Pressure). Results. Overall, thirty-eight patients participated. All could simulate snoring. Correlation coefficients were statistically significant between Quiet Pressures and body mass index (rs=0.60 [strong positive relationship], p=0.0088), apnea-hypopnea index (rs=0.49 [moderate positive relationship], p=0.039), lowest oxygen saturation (rs=-0.47 [moderate negative relationship], p=0.048), and oxygen desaturation index (rs=0.62 [strong positive relationship], p=0.0057). Conclusion. This pilot study introduces a new concept, which is the final product of over one year of exploration, development, and testing. Five-Minute CPAP Test is a quick, inexpensive, and safe bedside test based on supine awake simulated snoring with nasal CPAP

The MSLT is repeatable in narcolepsy type 1 but not narcolepsy type 2: A retrospective patient study

Study Objectives: To examine repeatability of Multiple Sleep Latency Test (MSLT) results in narcolepsy type 1 (NT1) and narcolepsy type 2 (NT2) according to the criteria of the International Classification of Sleep Disorders, Third Edition (ICSD-3). Methods: Repeatability of the MSLT was retrospectively evaluated in NT1 (n = 60) and NT2 (n = 54) cases, and controls (n = 15). All subjects had documented HLA-DQB1. 06:02 status and/or hypocretin-1 levels from cerebrospinal fluid. All subjects had undergone 2 MSLTs (⥠1 meeting ICSD-3 criteria for narcolepsy). Repeatability was explored in children versus adults and in those on versus not on medication(s). Subsample and multivariate analysis were performed. Results: Both MSLTs in unmedicated patients were positive for narcolepsy in 78%, 18%, and 7% of NT1, NT2, and controls, respectively. NT2 cases changed to idiopathic hypersomnia or to a negative MSLT 26% and 57% of the time, respectively. Although NT1 cases were 10 to 14 times more likely to demonstrate a second positive MSLT compared to NT2 cases (P < 10-5) and controls (P < 10-4), respectively, NT2 cases were not significantly different from controls (P = .64). Medication use (P = .009) but not adult versus children status (P = .85) significantly decreased the likelihood of a repeat positive MSLT. Conclusions: In a clinical setting, a positive MSLT for narcolepsy is a more reproducible and stable feature in NT1 than NT2. The retrospective design of this study hinders interpretation of these data, as there are many different, and possibly opposing, reasons to repeat a MSLT in NT1 versus NT2 (ie, ascertainment bias). Additional systematic MSLT repeatability studies independent of confounds are ideally needed to confirm these findings