Decreased body mass index during treatment with sodium oxybate in narcolepsy type 1

Cardiovascular Risks in People With Narcolepsy: Expert Panel Consensus Recommendations

BACKGROUND

Observational and retrospective studies suggest that people with narcolepsy may have an increased prevalence of cardiovascular and cardiometabolic comorbidities and may be at greater risk for future cardiovascular events. An expert consensus panel was formed to establish agreement on the risk of hypertension and cardiovascular/cardiometabolic disease in people with narcolepsy and to develop strategies to mitigate these risks.

METHODS AND RESULTS

Experts in sleep medicine and cardiology were selected to participate in the panel. After reviewing the relevant literature, the experts identified key elements, drafted recommendation statements, and developed discussion points to provide supporting evidence for the recommendations. The draft and final recommendations were rated on a scale from 0 (not at all agree) to 4 (very much agree). All experts had an agreement rating of 4.0 for all 14 revised recommendation statements for patients with narcolepsy. These statements comprised 3 themes: (1) recognize the risk of hypertension and cardiovascular/cardiometabolic disease, (2) reduce the risk of hypertension and cardiovascular/cardiometabolic disease, and (3) reduce sodium intake to lower the risk of hypertension and cardiovascular disease.

CONCLUSIONS

These consensus recommendations are intended to increase awareness of potential cardiovascular/cardiometabolic risks in patients with narcolepsy for all clinicians. Early monitoring for, and prevention of, cardiovascular risks in this population are of great importance, especially as narcolepsy usually develops in adolescents and young adults, who will be exposed to adverse effects of the disease for decades. Prospective systematic studies are needed to determine association and causation of narcolepsy with cardiovascular/cardiometabolic disorders.

Weight Loss With Once-nightly Sodium Oxybate for the Treatment of Narcolepsy: Analysis From the Phase III Randomized study Evaluating the efficacy and SafeTy of a ONce nightly formulation of sodium oxybate (REST-ON) Trial

PURPOSE

Individuals with narcolepsy are more likely to be obese than the general population. Changes in weight-related measures with extended-release, once-nightly sodium oxybate (ON-SXB) and characteristics of participants with ≥5% weight loss were assessed in a Randomized study Evaluating the efficacy and SafeTy of a ONce nightly formulation of sodium oxybate (REST-ON) trial post hoc analysis.

METHODS

REST-ON (NCT02720744) was a Phase III, double-blind, placebo-controlled, multicenter, randomized clinical trial. Participants aged ≥16 years with narcolepsy type 1 (NT1) or NT2 received ON-SXB or placebo for 13 weeks (week 1, 4.5 g; weeks 2-3, 6 g; weeks 4-8, 7.5 g; and weeks 9-13, 9 g). Weight and body mass index were measured at baseline and study end.

FINDINGS

Weights were similar between groups at baseline (mean [SD]; ON-SXB, 81.2 [20.8] kg; N = 107 [NT1, n = 80; NT2, n = 27]; placebo, 82.1 [22.5] kg; N = 105 [NT1, n = 82; NT2, n = 23]). At week 13 (9 g), mean (SD) weight decreased 1.3 (3.6) kg with ON-SXB and increased 0.2 (2.6) kg with placebo; 17.8% (19/107; NT1, n = 14; NT2, n = 5) of participants receiving ON-SXB had ≥5% weight loss versus 3.8% receiving placebo (4/105; NT1, n = 3; NT2, n = 1; P = 0.001). At week 13, least squares mean (SE) body mass index change from baseline was ‒0.51 (0.13) kg/m2 with ON-SXB and 0.08 (0.13) kg/m2 with placebo (least squares mean difference [95% CI], -0.59 [-0.95 to -0.23] kg/m2; P = 0.001). Excessive daytime sleepiness improved for both groups with ON-SXB, the ≥5% weight-loss subgroup exhibited larger improvement in the Maintenance of Wakefulness Test and Epworth Sleepiness Scale versus the other subgroup (weight loss <5%, no change, or weight gain) (Maintenance of Wakefulness Test, P = 0.019; Epworth Sleepiness Scale score, P < 0.001).

IMPLICATIONS

Narcolepsy is often associated with obesity, which may increase cardiometabolic risks. ON-SXB, an effective treatment for excessive daytime sleepiness and cataplexy, may be preferred in overweight or obese individuals to provide a more tailored treatment approach.

CLINICALTRIALS

GOV IDENTIFIER

NCT02720744.

Dosing Optimization of Low-Sodium Oxybate in Narcolepsy and Idiopathic Hypersomnia in Adults: Consensus Recommendations

INTRODUCTION

Low-sodium oxybate (LXB) is approved for treatment of narcolepsy in patients aged 7 years and older and treatment of idiopathic hypersomnia in adults. LXB contains the same active moiety with 92% less sodium than sodium oxybate (SXB). As the indication for oxybate treatment in patients with idiopathic hypersomnia is new and allows for individualized dosing optimization, guidance for beginning LXB treatment is needed. In particular, clinicians may benefit from guidance regarding treatment initiation, dosing/regimen options, potential challenges, and treatment expectations. Additionally, pharmacokinetic profiles differ slightly between both treatments, and further guidance on transitioning from SXB to LXB in patients with narcolepsy may aid clinicians.

METHODS

An expert panel of five sleep specialists was convened to obtain consensus on recommendations for these topics using a modified Delphi process.

RESULTS

Across two virtual meetings, the panel agreed on 31 recommendations with a high degree of consensus that fell into four overarching topics: (1) introducing LXB to patients; (2) initiating LXB for adult narcolepsy and idiopathic hypersomnia; (3) addressing challenges in using LXB; and (4) transitioning from SXB to LXB. The panel recommended that clinicians provide a clear overview of how LXB works for treating symptoms in narcolepsy or idiopathic hypersomnia, as appropriate for their patients, explain safety aspects, and set expectations prior to initiating LXB treatment. Strategies for initial dosing and regimen are provided. Strategies for adjusting the dose, regimen, timing, and consideration of individual factors were developed for specific instances in which patients may have trouble staying asleep or waking up, as well as guidance for addressing potential adverse events, such as nausea, dizziness, anxiety, and depression. Discussion points based on existing literature and clinical experience were included as relevant for each statement.

CONCLUSION

Clinicians may use this resource to guide LXB dosing optimization with patients.

Effect of sodium oxybate on body mass index in pediatric patients with narcolepsy

STUDY OBJECTIVES

We examined body mass index (BMI) changes associated with sodium oxybate treatment (SXB) in pediatric patients with narcolepsy with cataplexy who participated in a double-blind, placebo-controlled, randomized withdrawal study and an open-label continuation period.

METHODS

Participants were aged 7-16 years at screening. SXB-naive participants titrated to twice-nightly dosing of SXB then entered a 2-week stable-dose period; participants taking SXB at study entry entered a 3-week stable-dose period. After a 2-week randomized withdrawal period, all participants entered an open-label safety period (OLP; main study duration: ≤ 52 weeks). Participants who completed the OLP were allowed to enter the open-label continuation period (an additional 1-2 years). BMI percentile categories were defined as underweight (< 5th), normal (5th to < 85th), overweight (≥ 85th to < 95th), and obese (≥ 95th).

RESULTS

Median BMI percentile decreased from baseline to OLP week 52 in SXB-naive participants who were normal weight at baseline (decreased from 77.0 to 35.0) or overweight/obese at baseline (98.0 to 86.7). Median BMI percentile decreased to a lesser extent in participants taking twice-nightly SXB at study entry who were normal weight at baseline (54.6 to 53.0) or overweight/obese at baseline (96.5 to 88.9). Shifts in BMI category from baseline to week 52 were sometimes noted. In SXB-naive participants, 9/10 (90.0%) who were overweight became normal weight, 7/25 (28.0%) who were obese became normal weight, 3/25 (12.0%) who were obese became overweight, and 1/16 (6.3%) who was normal weight became obese. In participants taking SXB at baseline, 5/8 (62.5%) who were overweight became normal weight, 3/6 (50.0%) who were obese became overweight, 1/14 (7.1%) who was normal weight became overweight, and 2/14 (14.3%) who were normal weight became underweight. Median BMI percentiles at months 6 and 12 of the open-label continuation period were similar to those at OLP end (OLP week 52). In SXB-naive participants, the evident BMI z-score decrease over time was relative to the screening values.

CONCLUSIONS

Decreases in BMI percentile and z-score, and downward shifts in BMI category, were observed within 1 year of SXB treatment in pediatric participants with narcolepsy with cataplexy. BMI decreases plateaued after approximately 1 year.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Name: A Multicenter Study of the Efficacy and Safety of Xyrem With an Open-Label Pharmacokinetic Evaluation and Safety Extension in Pediatric Subjects With Narcolepsy With Cataplexy; URL: https://clinicaltrials.gov/study/NCT02221869; Identifier: NCT02221869.

CITATION

Dauvilliers Y, Lammers GJ, Lecendreux M, et al. Effect of sodium oxybate on body mass index in pediatric patients with narcolepsy. J Clin Sleep Med. 2024;20(3):445-454.

Individualized Treatment Patterns for Patients with Narcolepsy Treated with Oxybate: A Clinical Practice Perspective

Purpose

Real-world data regarding divided nightly dosing of oxybate and individualized prescribing in patients with narcolepsy are limited. Study objectives were to understand oxybate prescribing practices, including optimizing dose regimens and adjusting dosing per occasional changes in patients' routines, and physician recommendations for representative patient scenarios.

Patients and Methods

A cross-sectional, web- and audio-based survey of physicians treating ≥2 patients with narcolepsy, prescribed nightly oxybate (sodium oxybate) dosing for ≥6 months, was conducted. Physicians were surveyed on patients' usual oxybate dosing regimens, frequency of and reasons for oxybate dosing-related discussions, and preferred methods for and perceptions of adjusting oxybate dosing. Physicians provided dosing-related guidance for 4 representative scenarios.

Results

Participating physicians (N=25) were neurologists (52%), psychiatrists (44%), and neuropsychiatrists (4%). Individualized oxybate prescribing practices were reflected by the variability of physicians' reporting of the percentage of their patients being prescribed once-nightly, twice-nightly, and thrice-nightly dosing regimens. Most physicians (68%) reported discussing adjusting individualized treatment to accommodate occasional changes to patients' routines; the most common reasons were consuming contraindicated beverages (alcohol; 65%) and travel (59%). Adjusting total nightly dose (68%) and dose timing (68%) were preferred adjustment methods. Most physicians (88%) felt the ability to individualize oxybate dosing was important and had a positive impact on ability to provide care. For each representative scenario, physicians provided several dose-adjustment recommendations, and physician responses encouraged patient participation in treatment decision-making.

Conclusion

Physicians provided guidance supportive of oxybate dose adjustments to accommodate occasional changes in patients' routines, and perceived individualized dosing as important in providing care.

Effectiveness and tolerability in people with narcolepsy transitioning from sodium oxybate to low-sodium oxybate: Data from the real-world TENOR study

OBJECTIVES

The Transition Experience of persons with Narcolepsy taking Oxybate in the Real-world (TENOR) study was conducted to provide real-world insight into the experience of people with narcolepsy switching from sodium oxybate (SXB) to low-sodium oxybate (LXB; 92% less sodium than SXB).

METHODS

TENOR is a patient-centric, prospective, observational, virtual-format study. Participants were adults with narcolepsy (type 1 or 2) who were transitioning from SXB to LXB treatment (±7 days from LXB initiation). Effectiveness and tolerability data were collected online from baseline (taking SXB) through 21 weeks (taking LXB) via daily and weekly diaries and questionnaires, including the Epworth Sleepiness Scale (ESS), the Functional Outcomes of Sleep Questionnaire, short version (FOSQ-10), and the British Columbia Cognitive Complaints Inventory (BC-CCI).

RESULTS

TENOR participants (N = 85) were 73% female with a mean (SD) age of 40.3 (13.0) years. Mean (SD) ESS scores decreased numerically throughout the transition from SXB to LXB (baseline: 9.9 [5.2]; week 21: 7.5 [4.7]), with 59.5% and 75.0% of participants having scores in the normal range (≤10) at baseline and week 21, respectively. Mean (SD) FOSQ-10 scores (baseline: 14.4 [3.4]; week 21: 15.2 [3.2]) and BC-CCI scores (baseline: 6.1 [4.4]; week 21: 5.0 [4.3]) also remained stable. The most common symptoms related to tolerability reported by participants at baseline were sleep inertia, hyperhidrosis, and dizziness (45.2%, 40.5%, and 27.4%, respectively), which decreased in prevalence by week 21 (33.8%, 13.2%, and 8.8%, respectively).

CONCLUSIONS

Findings from TENOR confirm maintenance of effectiveness and tolerability when transitioning from SXB to LXB treatment.

Long-Term Treatment of Narcolepsy and Idiopathic Hypersomnia with Low-Sodium Oxybate

Narcolepsy and idiopathic hypersomnia are chronic conditions that negatively affect alertness, mental and physical energy, functioning, and quality of life (QoL). Calcium, magnesium, potassium, and sodium oxybates (low-sodium oxybate; LXB) is an oxybate formulation with 92% less sodium than sodium oxybate (SXB; a treatment for narcolepsy) and the same active moiety. LXB is approved in the US for treatment of cataplexy or excessive daytime sleepiness (EDS) in patients 7 years of age or older with narcolepsy, and idiopathic hypersomnia in adults. In Phase 3 clinical trials, LXB exhibited a safety profile consistent with that of SXB in narcolepsy. Besides continued efficacy in treating symptoms, potential benefits of long-term LXB treatment include flexible optimization of dosing and regimen, improvement of QoL and functioning, weight loss, and (relative to SXB in narcolepsy) health benefits of reduced sodium content. Dosing of LXB is twice nightly (for narcolepsy) or once or twice nightly (for idiopathic hypersomnia) based on patient characteristics and response, and individualized titration can be leveraged over the long term as a patient's life circumstances change. Patients with narcolepsy transitioning from SXB initiate LXB at the same dose, and most patients require no further changes to achieve similar efficacy and tolerability. Improvements in functioning and QoL with LXB treatment could have cascading positive effects in multiple domains, particularly in younger patients. In clinical trials, LXB was associated with weight loss in both narcolepsy (in which obesity is a well-established comorbidity) and idiopathic hypersomnia, only occasionally leading participants to be underweight. As both narcolepsy and idiopathic hypersomnia are associated with increased risk of cardiometabolic and cardiovascular comorbidities, limiting medication-related sodium intake with LXB may have significant health benefits, although this has not yet been verified prospectively due to the prolonged follow-up required. LXB is a promising long-term treatment for narcolepsy and idiopathic hypersomnia.

Auxological and endocrine findings in narcolepsy type 1: seventeen-year follow-up from a pediatric endocrinology center

Introduction

Narcolepsy Type 1 (NT1) is a rare hypersomnia of central origin linked to hypocretin deficiency, most frequently arising at pediatric age. NT1 could be associated with endocrine comorbidities involving the neuroendocrine axis, predominantly obesity, and Central Precocious Puberty (CPP). The primary aim of this study is the evaluation of endocrine and auxological parameters at diagnosis and during follow-up in patients with NT1, treated with Sodium Oxybate (SO) or not.

Methods

We retrospectively evaluated the auxological, biochemical, and radiological parameters of 112 patients referred to our Center between 2004-2022. The design of our study is cross-sectional at the time of diagnosis followed by a longitudinal follow-up.

Results

Our study confirms an increased frequency of CPP and obesity in patients with NT1. At first evaluation, obesity was found in 31.3% of patients, while overweight was found in 25.0%. A diagnosis of CPP was made in 19.6% of patients. Interestingly, this group showed a significantly lower level of CSF-hypocretin (hrct-1) at diagnosis compared to others. We found an improvement in BMI SDS in the SO-treated group compared to untreated patients, and this trend persisted also at 36 months of follow-up (0.0 ± 1.3 vs 1.3 ± 0.4; p<0.03). Sixty-three patients reached their final height, with a median SDS of 0.6 ± 1.1 in boys and 0.2 ± 1.2 in girls.

Discussion

To our knowledge, these are the first results regarding the final height in a large series of pediatric patients with NT1, with a normal range of IGF1-SDS levels and stature SDS.

Long-Term Safety and Tolerability During a Clinical Trial and Open-Label Extension of Low-Sodium Oxybate in Participants with Narcolepsy with Cataplexy

BACKGROUND

The safety and efficacy of low-sodium oxybate (LXB; Xywav^®) were established in a randomized, double-blind, placebo-controlled, phase 3 withdrawal study in adults with narcolepsy with cataplexy; however, the longer-term safety profile has not yet been examined. The aim of the current analysis was to assess the time of onset and duration of common treatment-emergent adverse events (TEAEs) for LXB throughout the open-label optimized treatment and titration period (OLOTTP) and the stable dose period (SDP) portions of the main study, and the subsequent 24-week open-label extension (OLE).

METHODS

In a double-blind, placebo-controlled, randomized withdrawal trial of LXB, TEAEs were evaluated during the 12-week OLOTTP, the 2-week SDP, and the subsequent 24-week OLE. Eligible participants were aged 18-70 years with a diagnosis of narcolepsy with cataplexy. At study entry, participants were taking sodium oxybate (SXB) alone, SXB with other anticataplectics, other anticataplectics alone, or were anticataplectic-treatment naive; other anticataplectics were tapered and discontinued during the OLOTTP. All participants initiated LXB during week 1 of the OLOTTP, and their dose was individually titrated based on safety and efficacy. Following the main study period, participants entered the OLE after rescreening (re-entry) after discontinuing LXB treatment or directly after completing the main study (rollover). TEAEs were assessed in the safety population as of database lock. TEAE duration was defined as time from TEAE start date to end date (or end of SDP or OLE, if end date was unrecorded).

RESULTS

The safety population included 201 participants (SXB alone, n = 52; SXB with other anticataplectics, n = 23; other anticataplectics alone, n = 36; anticataplectic-treatment naive, n = 90). During the OLOTTP/SDP, headache was the most common LXB-emergent TEAE overall (71 events; n = 42 (21%); median (range) duration = 1 (1-147) day), followed by nausea (31 events; n = 26 (13%); median (range) duration = 9 (1-54) days) and dizziness (26 events; n = 21 (10%); median (range) duration = 7 (1-117) days). Among the 74 participants in the OLE, the most commonly reported TEAEs were headache (14 events; n = 7, 9%; peak incidence month 3 (n = 5/72); median (range) duration = 1 (1‒25) day), dizziness (8 events; n = 5, 7%; peak incidence month 1 (n = 3/74); median (range) duration = 26 (1‒181) days), and nasopharyngitis (6 events; n = 6, 8%; peak incidence month 6 (n = 2/69); median (range) duration = 9 (1‒24) days). Overall, study discontinuations attributed to TEAEs were 21/65 (32%) during the OLOTTP and SDP and 3/7 (43%) during the OLE.

CONCLUSIONS

In this long-term analysis, the safety and tolerability profile of LXB was generally consistent with the known safety profile of SXB. During the OLOTTP and SDP, most TEAEs occurred early and were generally of short duration. TEAE prevalence decreased throughout the duration of the OLE; the most common TEAEs reported during the OLE were headache, dizziness, and nasopharyngitis.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT03030599 (25 January 2017).

Update on the treatment of idiopathic hypersomnia: Progress, challenges, and expert opinion

Idiopathic hypersomnia is a central hypersomnolence disorder of unknown origin characterized by excessive daytime sleepiness despite normal or long sleep time, and frequent severe sleep inertia. Management strategies have been largely derived from expert consensus, due to a lack of disease-specific assessments and reliance on case series and rare randomized controlled studies. Guidelines recommend treatment with off-label medications. Modafinil, which was approved for idiopathic hypersomnia until 2011 in Europe, is the most commonly used treatment and improved sleepiness in two recent randomized placebo-controlled trials. In 2021, low-sodium oxybate (LXB) was approved in the United States for idiopathic hypersomnia. In a placebo-controlled, double-blind, randomized withdrawal study, LXB reduced daytime sleepiness and sleep inertia, and improved daily functioning. Here, treatment options are reviewed considering the authors' professional experience, current guidelines, and the latest research developments. The choice of pharmacotherapy should be guided by symptom profile, age, comorbidities (eg, depressive symptoms, cardiovascular problems), and concomitant medications (eg, oral contraceptives). Nonpharmacologic approaches have a role in management. An instrument (idiopathic hypersomnia severity scale) has been validated in idiopathic hypersomnia specifically, opening a path to better assessment of symptoms, impact, and response to treatment. Continued research on idiopathic hypersomnia is needed to support treatment algorithms.

Danavorexton, a selective orexin 2 receptor agonist, provides a symptomatic improvement in a narcolepsy mouse model

Narcolepsy type 1 (NT1), caused by loss of orexin neurons, is a neurological disorder characterized by excessive daytime sleepiness, cataplexy, disrupted nighttime sleep, hypnagogic/hypnopompic hallucinations and sleep paralysis, as well as a high risk of obesity. Danavorexton (TAK-925) is a novel brain-penetrant orexin 2 receptor (OX2R)-selective agonist currently being evaluated in clinical trials for the treatment of hypersomnia disorders including NT1. Thus, detailed characterization of danavorexton is critical for validating therapeutic potential of OX2R-selective agonists. Here, we report preclinical characteristics of danavorexton as a therapeutic drug for NT1. Danavorexton showed rapid association/dissociation kinetics to OX2R. The activation mode of endogenous OX2R by danavorexton and orexin peptide was very similar in an electrophysiological analysis. In orexin/ataxin-3 mice, a mouse model of NT1, danavorexton promoted wakefulness, and ameliorated fragmentation of wakefulness during the active phase after both acute and repeated administration, suggesting a low risk of receptor desensitization. Electroencephalogram (EEG) power spectral analysis revealed that danavorexton, but not modafinil, normalized dysregulated EEG power spectrum in orexin/ataxin-3 mice during the active phase. Finally, repeated administration of danavorexton significantly suppressed the body weight gain in orexin/ataxin-3 mice. Danavorexton may have the potential to treat multiple symptoms of NT1. These preclinical findings, together with upcoming clinical observations of danavorexton, could improve our understanding of the pathophysiology of NT1 and therapeutic potential of OX2R agonists.

Toxicological Characterization of GHB as a Performance-Enhancing Drug

Performance-enhancing drugs (PEDs) are represented by several compounds used to ameliorate the image, the appearance, or an athletic or non-athletic performance. Gamma-hydroxybutyrate (GHB) is an endogenous molecule first used as anesthetic and then marketed as a nutritional supplement with a wide diffusion in the bodybuilding community. The aim of the present work is to provide a toxicological characterization of the use of GHB as a PED, including the scientific basis for its use, the patterns of use/abuse, and the health risks arising from its consumption in this peculiar recreative setting. A literature search was performed on multiple databases including experimental studies on humans and animals as well as epidemiological reports and forensic case reports/series. Experimental studies demonstrated that the use of GHB as a PED is motivated by the release of growth hormone and the induction of sleep. However, the panel of desired performance-related effects was much wider in real cases and epidemiological studies. Even though the use of GHB among bodybuilders has decreased, its use to enhance some kind of performance, particularly sexual ones or social-communicative ones, as well as means to increase mood and perceived energy, is still common.

BMI changes in pediatric type 1 narcolepsy under sodium oxybate treatment

Pediatric type 1 narcolepsy (NT1) is often associated with overweight and obesity. Sodium oxybate (SO), approved for the treatment of narcolepsy with cataplexy from the age of 7 years old in the United States, has been associated with weight loss, although longitudinal pediatric studies are lacking. We report a retrospective cohort of 129 consecutive patients with a 4-year follow-up, to analyze the impact of different pharmacological treatments on body mass index (BMI) z-score. At baseline, the prevalence of obesity and overweight was 26.4% (34/129) and 29.5% (38/129), respectively. Patients were divided into three groups: children treated with SO alone (group 1), with SO-combined therapy (group 2), and without SO (group 3). At the end of the first year of follow-up, group 1 and group 2 showed a significant BMI z-score reduction compared to baseline: from 1.2 ± 1.1 to 0.4 ± 1.4 for group 1 (p < 0.001), and from 1.4 ± 1.1 to 1 ± 1.3 for group 2 (p = 0.002), independently from baseline clinical features. In the second year, only group 2 experienced a further and significant BMI z-score decrease (from 1.0 ± 1.2 to 0.6 ± 1.2, p = 0.037). No further significant BMI z-score changes were observed in SO-treated patients in the following years. Instead, children treated without SO developed a significant weight increase between the second and third year of therapy (BMI z-score from 0.3 ± 0.9 to 0.5 ± 0.9). In conclusion, SO treatment in pediatric NT1 is associated with a favorable weight reduction in the first year of treatment.

European guideline and expert statements on the management of narcolepsy in adults and children

BACKGROUND AND PURPOSE

Narcolepsy is an uncommon hypothalamic disorder of presumed autoimmune origin that usually requires lifelong treatment. This paper aims to provide evidence-based guidelines for the management of narcolepsy in both adults and children.

METHODS

The European Academy of Neurology (EAN), European Sleep Research Society (ESRS), and European Narcolepsy Network (EU-NN) nominated a task force of 18 narcolepsy specialists. According to the EAN recommendations, 10 relevant clinical questions were formulated in PICO format. Following a systematic review of the literature (performed in Fall 2018 and updated in July 2020) recommendations were developed according to the GRADE approach.

RESULTS

A total of 10,247 references were evaluated, 308 studies were assessed and 155 finally included. The main recommendations can be summarized as follows: (i) excessive daytime sleepiness (EDS) in adults-scheduled naps, modafinil, pitolisant, sodium oxybate (SXB), solriamfetol (all strong); methylphenidate, amphetamine derivatives (both weak); (ii) cataplexy in adults-SXB, venlafaxine, clomipramine (all strong) and pitolisant (weak); (iii) EDS in children-scheduled naps, SXB (both strong), modafinil, methylphenidate, pitolisant, amphetamine derivatives (all weak); (iv) cataplexy in children-SXB (strong), antidepressants (weak). Treatment choices should be tailored to each patient's symptoms, comorbidities, tolerance and risk of potential drug interactions.

CONCLUSION

The management of narcolepsy involves non-pharmacological and pharmacological approaches with an increasing number of symptomatic treatment options for adults and children that have been studied in some detail.

European guideline and expert statements on the management of narcolepsy in adults and children

BACKGROUND AND AIM

Narcolepsy is an uncommon hypothalamic disorder of presumed autoimmune origin that usually requires lifelong treatment. This paper aims to provide evidence-based guidelines for the management of narcolepsy in both adults and children.

METHODS

The European Academy of Neurology (EAN), European Sleep Research Society (ESRS) and European Narcolepsy Network (EU-NN) nominated a task force of 18 narcolepsy specialists. According to the EAN recommendations, 10 relevant clinical questions were formulated in PICO format. Following a systematic review of the literature (performed in Fall 2018 and updated in July 2020) recommendations were developed according to the GRADE approach.

RESULTS

A total of 10,247 references were evaluated, 308 studies were assessed and 155 finally included. The main recommendations can be summarized as follows: (i) excessive daytime sleepiness in adults-scheduled naps, modafinil, pitolisant, sodium oxybate (SXB), solriamfetol (all strong), methylphenidate, amphetamine derivates (both weak); (ii) cataplexy in adults-SXB, venlafaxine, clomipramine (all strong) and pitolisant (weak); (iii) excessive daytime sleepiness in children-scheduled naps, SXB (both strong), modafinil, methylphenidate, pitolisant, amphetamine derivates (all weak); (iv) cataplexy in children-SXB (strong), antidepressants (weak). Treatment choices should be tailored to each patient's symptoms, comorbidities, tolerance and risk of potential drug interactions.

CONCLUSION

The management of narcolepsy involves non-pharmacological and pharmacological approaches with an increasing number of symptomatic treatment options for adults and children that have been studied in some detail.

Sodium Oxybate: A Cause of Extreme Involuntary Weight Loss in a Young Lady

We present a case of a young lady with extreme involuntary weight loss and alarming constitutional symptoms found ultimately to be all due to a single medication's side effects. The objective of this case report is to alert physicians, especially in a primary care setting, that the side effects of a medication used mostly in a highly specialized field of neurology, sodium oxybate (SXB), can cause extreme involuntary weight loss in addition to chronic night sweats and symptoms of clinical depression.

Decreased body mass index during treatment with sodium oxybate in narcolepsy type 1

Narcolepsy type 1 is characterised by an increase in body weight after disease onset, frequently leading to obesity. It was suggested that this weight gain may be counteracted by treatment with sodium oxybate. We here provide longitudinal body mass index data of patients with narcolepsy type 1 after starting treatment with sodium oxybate, compared with patients in whom treatment with modafinil was initiated. Eighty-one individuals with narcolepsy type 1 fulfilled the entry criteria for this retrospective study: 59 had newly started treatment with sodium oxybate and 22 had newly started modafinil. Gender-specific differences between both treatment groups were compared using Student's t tests and mixed effect modeling. Patients using sodium oxybate lost weight, with a mean body mass index decrease of 2.56 kg/m2 between the first and last measurement (women; p = .001) and 0.84 kg/m2 (men; p = .006). Patients using modafinil, however, gained weight, with a mean body mass index increase of 0.57 kg/m2 (women; p = .033) and 0.67 kg/m2 (men; p = .122). Medication (p = .006) and baseline body mass index (p = .032) were predictors for body mass index decrease. In conclusion, treatment with sodium oxybate is associated with a body mass index reduction in narcolepsy type 1, whereas modafinil treatment is not. This effect is most pronounced in those who already have a higher baseline body mass index.

Enhanced food-related responses in the ventral medial prefrontal cortex in narcolepsy type 1

Narcolepsy type 1 is a chronic sleep disorder caused by a deficiency of the orexin (hypocretin) neuropeptides. In addition to sleep regulation, orexin is important for motivated control processes. Weight gain and obesity are common in narcolepsy. However, the neurocognitive processes associated with food-related control and overeating in narcolepsy are unknown. We explored the neural correlates of general and food-related attentional control in narcolepsy-type-1 patients (n = 23) and healthy BMI-matched controls (n = 20). We measured attentional bias to food words with a Food Stroop task and general executive control with a Classic Stroop task during fMRI. Moreover, using multiple linear regression, we assessed the relative contribution of neural responses during Food Stroop and Classic Stroop to spontaneous snack intake. Relative to healthy controls, narcolepsy patients showed enhanced ventral medial prefrontal cortex responses and connectivity with motor cortex during the Food Stroop task, but attenuated dorsal medial prefrontal cortex responses during the Classic Stroop task. Moreover, the former activity but not the latter, was a significant predictor of spontaneous snack intake. These findings demonstrate that narcolepsy, characterized by orexin deficiency, is associated with decreased dorsal medial prefrontal cortex responses during general executive control and enhanced ventral medial prefrontal cortex responses during food-driven attention.