Oral Orexin Receptor 2 Agonist in Narcolepsy Type 1.

BACKGROUND: Narcolepsy type 1 is caused by severe loss or lack of brain orexin neuropeptides. METHODS: We conducted a phase 2, randomized, placebo-controlled trial of TAK-994, an oral orexin receptor 2-selective agonist, in patients with narcolepsy type 1. Patients with confirmed narcolepsy type 1 according to clinical criteria were randomly assigned to receive twice-daily oral TAK-994 (30 mg, 90 mg, or 180 mg) or placebo. The primary end point was the mean change from baseline to week 8 in average sleep latency (the time it takes to fall asleep) on the Maintenance of Wakefulness Test (range, 0 to 40 minutes; normal ability to stay awake, ≥20 minutes). Secondary end points included the change in the Epworth Sleepiness Scale (ESS) score (range, 0 to 24, with higher scores indicating greater daytime sleepiness; normal, <10) and the weekly cataplexy rate. RESULTS: Of the 73 patients, 17 received TAK-994 at a dose of 30 mg twice daily, 20 received 90 mg twice daily, 19 received 180 mg twice daily, and 17 received placebo. The phase 2 trial and an extension trial were terminated early owing to hepatic adverse events. Primary end-point data were available for 41 patients (56%); the main reason for missing data was early trial termination. Least-squares mean changes to week 8 in average sleep latency on the MWT were 23.9 minutes in the 30-mg group, 27.4 minutes in the 90-mg group, 32.6 minutes in the 180-mg group, and -2.5 minutes in the placebo group (difference vs. placebo, 26.4 minutes in the 30-mg group, 29.9 minutes in the 90-mg group, and 35.0 minutes the 180-mg group; P<0.001 for all comparisons). Least-squares mean changes to week 8 in the ESS score were -12.2 in the 30-mg group, -13.5 in the 90-mg group, -15.1 in the 180-mg group, and -2.1 in the placebo group (difference vs. placebo, -10.1 in the 30-mg group, -11.4 in the 90-mg group, and -13.0 in the 180-mg group). Weekly incidences of cataplexy at week 8 were 0.27 in the 30-mg group, 1.14 in the 90-mg group, 0.88 in the 180-mg group, and 5.83 in the placebo group (rate ratio vs. placebo, 0.05 in the 30-mg group, 0.20 in the 90-mg group, and 0.15 in the 180-mg group). A total of 44 of 56 patients (79%) receiving TAK-994 had adverse events, most commonly urinary urgency or frequency. Clinically important elevations in liver-enzyme levels occurred in 5 patients, and drug-induced liver injury meeting Hy's law criteria occurred in 3 patients. CONCLUSIONS: In a phase 2 trial involving patients with narcolepsy type 1, an orexin receptor 2 agonist resulted in greater improvements on measures of sleepiness and cataplexy than placebo over a period of 8 weeks but was associated with hepatotoxic effects. (Funded by Takeda Development Center Americas; TAK-994-1501 and TAK-994-1504 ClinicalTrials.gov numbers, NCT04096560 and NCT04820842.).

Safety and pharmacodynamics of a single infusion of danavorexton in adults with obstructive sleep apnea experiencing excessive daytime sleepiness despite adequate use of CPAP.

BACKGROUND: Sleep disruptions experienced by patients with obstructive sleep apnea (OSA) can lead to excessive daytime sleepiness (EDS) and significantly impact patients' quality of life. EDS may persist despite use of continuous positive airway pressure (CPAP) therapy. Small molecules that target the orexin system, which has a known role in sleep-wake regulation, show therapeutic potential for the treatment of EDS in patients with hypersomnia. This randomized, placebo-controlled, phase 1b study aimed to investigate the safety of danavorexton, a small-molecule orexin-2 receptor agonist, and its effects on residual EDS in patients with OSA. METHODS: Adults with OSA aged 18-67 years with adequate CPAP use were randomized to one of six treatment sequences of single IV infusions of danavorexton 44 mg, danavorexton 112 mg, and placebo. Adverse events were monitored throughout the study. Pharmacodynamic assessments included maintenance of wakefulness test (MWT), Karolinska Sleepiness Scale (KSS), and the psychomotor vigilance test (PVT). RESULTS AND CONCLUSION: Among 25 randomized patients, 16 (64.0%) had treatment-emergent adverse events (TEAEs) and 12 (48.0%) had TEAEs considered related to treatment, all mild or moderate. Seven patients (28.0%) had urinary TEAEs: three, seven, and none while taking danavorexton 44 mg, danavorexton 112 mg, and placebo, respectively. There were no deaths or TEAEs leading to discontinuation. Improvements in mean MWT, KSS, and PVT scores were observed with danavorexton 44 mg and 112 mg vs placebo. These findings show that danavorexton can improve subjective and objective measures of EDS in patients with OSA and residual EDS despite adequate CPAP use.

Safety and pharmacodynamics of a single infusion of danavorexton in adults with idiopathic hypersomnia.

STUDY OBJECTIVES: Idiopathic hypersomnia (IH) is a chronic disorder characterized by excessive daytime sleepiness unexplained by another disorder or drug/medication use. Although the orexin system plays a role in sleep-wake regulation, orexin A levels in the cerebrospinal fluid are normal in people with IH. This phase 1b, randomized, placebo-controlled, crossover study aimed to investigate the safety, pharmacokinetics, and pharmacodynamics of danavorexton, a small-molecule orexin-2 receptor agonist, in adults with IH. METHODS: Adults with IH aged 18-75 years were randomized to one of two treatment sequences of single intravenous infusions of danavorexton 112 mg and placebo. Pharmacodynamic endpoints included the maintenance of wakefulness test (MWT), the Karolinska Sleepiness Scale (KSS), and the psychomotor vigilance task (PVT). Adverse events were monitored throughout the study period. RESULTS: Of 28 randomized participants, 12 (44.4%) had a treatment-emergent adverse event (TEAE) and 10 (37.0%) had a TEAE considered related to study drug, most of which were mild or moderate. Four participants (18.2%) had urinary TEAEs while receiving danavorexton, all of which were mild in severity. There were no deaths or TEAEs leading to discontinuation. Improvements in MWT, KSS, and PVT scores were observed with danavorexton compared to placebo. Following drug administration, a mean sleep latency of 40 min (maximum value) was observed during the MWT within 2 h of danavorexton infusion in most participants. CONCLUSIONS: A single infusion of danavorexton improves subjective and objective excessive daytime sleepiness in people with IH with no serious TEAEs, indicating orexin-2 receptor agonists are promising treatments for IH. Clinical Trial: Clinicaltrials.gov. https://clinicaltrials.gov/ct2/show/NCT04091438.

Treatment of central disorders of hypersomnolence: an American Academy of Sleep Medicine systematic review, meta-analysis, and GRADE assessment.

INTRODUCTION: This systematic review provides supporting evidence for the accompanying clinical practice guideline on the treatment of central disorders of hypersomnolence in adults and children. The review focuses on prescription medications with U.S. Food & Drug Administration approval and nonpharmacologic interventions studied for the treatment of symptoms caused by central disorders of hypersomnolence. METHODS: The American Academy of Sleep Medicine commissioned a task force of experts in sleep medicine to perform a systematic review. Randomized controlled trials and observational studies addressing pharmacological and nonpharmacological interventions for central disorders of hypersomnolence were identified. Statistical analyses were performed to determine the clinical significance of all outcomes. Finally, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) process was used to assess the evidence for the purpose of making specific treatment recommendations. RESULTS: The literature search identified 678 studies; 144 met the inclusion criteria and 108 provided data suitable for statistical analyses. Evidence for the following interventions is presented: armodafinil, clarithromycin, clomipramine, dextroamphetamine, flumazenil, intravenous immune globulin (IVIG), light therapy, lithium, l-carnitine, liraglutide, methylphenidate, methylprednisolone, modafinil, naps, pitolisant, selegiline, sodium oxybate, solriamfetol, and triazolam. The task force provided a detailed summary of the evidence along with the quality of evidence, the balance of benefits and harms, patient values and preferences, and resource use considerations. CITATION: Maski K, Trotti LM, Kotagal S, et al. Treatment of central disorders of hypersomnolence: an American Academy of Sleep Medicine systematic review, meta-analysis, and GRADE assessment. J Clin Sleep Med. 2021;17(9):1895-1945.

Longitudinal study of narcolepsy symptoms in first, second, and third-degree relatives of simplex and multiplex narcolepsy families.

OBJECTIVE: To assess the evolution of narcolepsy symptoms in first-, second, and third-degree relatives and to compare multiplex and simplex families. METHODS: A total of 4045 family members and 362 narcoleptic individuals were entered in the study; with 3255 family members interviewed twice, five to seven years apart. A control group (n = 178) composed of spouses or housemates was also interviewed twice. Family members were divided according to their blood relationship with the probands and further divided into multiplex (ie, more than one narcolepsy cases) and simplex (only one narcolepsy case) families. Telephone interviews were conducted with the help of the Sleep-EVAL system; narcolepsy probands were evaluated and diagnosed by a Sleep Specialist in a Sleep Clinic Center. RESULTS: A total of 1123 family members from 72 families were identified as members of multiplex families while the rest of the sample were a part of simplex families (n = 2132). Multiplex families had higher incidence and chronicity of hypersomnolence than the simplex family members and the control group. For cataplexy-like symptoms, only prevalence at the time of the first assessment distinguished multiplex (5.5%) and simplex (2.9%) families. Prevalence of sleep paralysis was higher among the first- and second-degree relatives coming from multiplex families, while incidence was the highest among second- and third-degree relatives. Hypnagogic hallucinations had similar prevalence between multiplex and simplex families but the incidence and chronicity were significantly higher among multiplex families. For each symptom, predictive factors were also determined in simplex and multiplex families. CONCLUSIONS: Our results show that individuals coming from multiplex families are at greater risks of a broad range of narcolepsy symptoms compared to simplex families.

Correlation of Changes in Patient-Reported Quality of Life With Physician-Rated Global Impression of Change in Patients With Narcolepsy Participating in a Clinical Trial of Sodium Oxybate: A Post Hoc Analysis.

INTRODUCTION: Narcolepsy patients report lower health-related quality of life (HRQoL) than the general population, as measured by the Short Form-36 Health Survey (SF-36). This analysis evaluated whether changes in SF-36 correlated with physician-rated Clinical Global Impression of Change (CGI-C). METHODS: Data were from 209 of 228 narcolepsy patients participating in an 8-week clinical trial of sodium oxybate. Changes from baseline for SF-36 subscales (Physical Functioning, Role Physical, Bodily Pain, General Health, Vitality, Social Functioning, Role Emotional, and Mental Health) and the summary scores were evaluated for correlation with CGI-C overall and by treatment group. Correlations were calculated using the Pearson product-moment correlation coefficient (r). RESULTS: Correlations described an inverse relationship in scores, but a direct relationship in improvement; lower CGI-C scores (i.e., better) were associated with higher SF-36 subscale scores (i.e., improved HRQoL). Moderate and significant correlations were observed for Vitality (r = -0.464; P < 0.0001) and Role Physical (r = -0.310; P < 0.0001) subscales, but weak correlations were observed with other subscales including summary scores. Correlations were stronger at higher sodium oxybate doses for most SF-36 subscales. CONCLUSION: Some aspects of HRQoL, measured by the SF-36, may be associated with narcolepsy. In particular, Vitality (indicative of energy and tiredness) and Role Physical (impact of physical function on daily roles) moderately correlated with overall change in status observed by clinicians. However, lack of strong correlations between SF-36 and CGI-C indicates differences in patient and clinician perspectives of disease, and suggest a need for broader assessment of the impact of narcolepsy and its treatment on patients. FUNDING: Jazz Pharmaceuticals.

Impact of sodium oxybate, modafinil, and combination treatment on excessive daytime sleepiness in patients who have narcolepsy with or without cataplexy.

BACKGROUND: Effects of sodium oxybate (SXB) on patients with narcolepsy with cataplexy (NC) or without cataplexy (NWOC) have not been separately evaluated in clinical trials. METHODS: Retrospective analysis evaluated data from a phase 3, randomized, placebo-controlled trial of SXB, modafinil, and SXB + modafinil versus placebo in adult NC patients (n = 95) or NWOC patients (n = 127). NC patients were identified based on medical history, concomitant medications, and sleep-onset REM periods on nocturnal polysomnography. The studied outcomes were changes from baseline at eight weeks on the Epworth Sleepiness Scale (ESS), the Maintenance of Wakefulness Test (MWT), and the Clinical Global Impression of Change (CGI-C). RESULTS: Among NC and NWOC patients, ESS improvement was significantly greater with SXB and SXB + modafinil versus placebo. In NC patients, mean MWT sleep latency was significantly increased with SXB + modafinil versus placebo. In NWOC patients, mean MWT sleep latency significantly increased in all groups versus placebo. Higher percentages of patients in the SXB and SXB + modafinil groups were "very much improved" or "much improved" on the CGI-C versus placebo in both NC and NWOC populations, although the difference did not reach statistical significance in the NWOC populations. Adverse events were consistent with previously-reported profiles for modafinil and SXB. Nausea was more common in the SXB and SXB + modafinil groups. Dizziness and tremor were more common in the SXB + modafinil group only. CONCLUSIONS: SXB alone and in combination with modafinil improved subjective ratings of excessive sleepiness and an objective measure of the ability to stay awake to similar extents in NC patients and NWOC patients.

Evaluation of Quality of Life in Patients With Narcolepsy Treated With Sodium Oxybate: Use of the 36-Item Short-Form Health Survey in a Clinical Trial.

INTRODUCTION: The present post hoc analysis was designed to evaluate health-related quality of life (HRQoL) using the 36-item Short Form Health Status Survey (SF-36) during an 8-week trial of sodium oxybate (SXB). METHODS: SF-36 was assessed in a phase 3 placebo-controlled trial in patients with narcolepsy (N = 228) randomized to placebo or SXB in doses of 4.5, 6, or 9 g nightly for 8 weeks. Changes from baseline in SF-36 (last observation carried forward) were compared between SXB and placebo, and effect sizes (ES) were estimated. RESULTS: Baseline SF-36 values were lower than normative values for the US general population. After 8 weeks of treatment, mean (±standard deviation) improvement from baseline on the Physical Component Summary (PCS) was significantly greater with SXB 9 g/night than placebo (6.3 ± 9.1 vs. 1.5 ± 6.2; p = 0.005), with moderate ES; no significant difference was found between the SXB and placebo groups on the Mental Component Summary. SXB 9 g/night resulted in significantly (p < 0.05) greater improvements than placebo in Physical Functioning (4.4 ± 9.2 vs. 1.0 ± 8.0), General Health (GH; 3.1 ± 7.0 vs. 0.4 ± 6.8), and Social Functioning (6.8 ± 16.8 vs. 1.1 ± 9.6). All SXB doses resulted in significant improvement (p < 0.05) relative to placebo for Vitality, with moderate ES. No significant differences versus placebo were observed for Role-Physical, Role-Emotional, or Mental Health domains. CONCLUSION: Treatment with SXB was associated with a dose-dependent improvement in HRQoL, with the 9-g nightly dose demonstrating a positive impact on PCS and individual SF-36 domains of Vitality, GH, and Physical and Social Functioning. TRIAL REGISTRATION: NCT00049803. FUNDING: Jazz Pharmaceuticals.

Effect of Oral JZP-110 (ADX-N05) on Wakefulness and Sleepiness in Adults with Narcolepsy: A Phase 2b Study.

STUDY OBJECTIVES: To evaluate the efficacy and safety of oral JZP-110, a second-generation wake-promoting agent with dopaminergic and noradrenergic activity, for treatment of impaired wakefulness and excessive sleepiness in adults with narcolepsy. METHODS: This was a phase 2b, randomized, double-blind, placebo-controlled, parallel-group trial conducted at 28 centers in the United States. Patients were adults with narcolepsy who had baseline scores ≥ 10 on the Epworth Sleepiness Scale (ESS) and baseline sleep latency ≤ 10 min on the Maintenance of Wakefulness Test (MWT). Patients received a daily placebo (n = 49) or JZP-110 (n = 44) 150 mg/day weeks 1-4 and 300 mg/day weeks 5-12. Primary efficacy endpoints were change from baseline in average MWT sleep latency, and the Clinical Global Impression-Change (CGI-C); secondary endpoints were change from baseline in ESS score and Patient Global Impression-Change. RESULTS: Improvements were significantly greater with JZP-110 versus placebo on mean MWT sleep latency (4 w, 9.5 versus 1.4 min, P < 0.0001; 12 w, 12.8 versus 2.1 min, P < 0.0001), percentage of patients with CGI-C improvement (4 w, 80% versus 51%, P = 0.0066; 12 w, 86% versus 38%, P < 0.0001), and mean change in ESS (4 w, -5.6 versus -2.4, P = 0.0038; 12 w, -8.5 versus -2.5, P < 0.0001). Three JZP-110-treated patients (6.8%) discontinued due to adverse events (AEs). The most common AEs with JZP-110 versus placebo were insomnia (23% versus 8%), headache (16% versus 10%), nausea (14% versus 6%), diarrhea (11% versus 6%), decreased appetite (14% versus 0%), and anxiety (11% versus 0%). CONCLUSIONS: At doses of 150-300 mg/day, JZP-110 was well tolerated and significantly improved the ability to stay awake and subjective symptoms of excessive sleepiness in adults with narcolepsy. CLINICAL TRIALS REGISTRATION: Clinicaltrials.gov identifier NCT01681121.

Treatment paradigms for cataplexy in narcolepsy: past, present, and future.

Cataplexy is defined as episodes of sudden loss of voluntary muscle tone triggered by emotions generally lasting <2 minutes. Cataplexy is most commonly associated with and considered pathognomonic for narcolepsy, a sleep disorder affecting ~0.05% of the general population. Knowledge of the pathophysiology of cataplexy has advanced through study of canine, murine, and human models. It is now generally considered that loss of signaling by hypothalamic hypocretin/orexin-producing neurons plays a key role in the development of cataplexy. Although the cause of hypocretin/orexin neuron loss in narcolepsy with cataplexy is unknown, an autoimmune etiology is widely hypothesized. Despite these advances, a literature review shows that treatment of cataplexy remains limited. Multiple classes of antidepressants have been commonly used off-label for cataplexy in narcolepsy and are suggested for this use in expert consensus guidelines based on traditional practice, case reports, and small trials. However, systematic research evidence supporting antidepressants for cataplexy is lacking. The single pharmacotherapy indicated for cataplexy and the guideline-recommended first-line treatment in Europe and the US is sodium oxybate, the sodium salt of gamma-hydroxybutyrate. Clinical trial evidence of its efficacy and safety in cataplexy is robust, and it is hypothesized that its therapeutic effects may occur through gamma-aminobutyric acid receptor type B-mediated effects at noradrenergic, dopaminergic, and thalamocortical neurons. Additional possible mechanisms for cataplexy therapy suggested by preliminary research include antagonism of the histamine H3 autoreceptor with pitolisant and intravenous immunoglobulin therapy for amelioration of the presumed autoimmune-mediated hypocretin/orexin cell loss. Further research and development of therapeutic approaches to cataplexy are needed.

A 12-week open-label, multicenter study evaluating the safety and patient-reported efficacy of sodium oxybate in patients with narcolepsy and cataplexy.

OBJECTIVE: This study aimed to evaluate safety and efficacy of sodium oxybate (SXB) titrated to effect. METHODS: SXB-naive patients who had participated in a randomized SXB clinical trial and had not been titrated to adequate clinical effect were initiated on open-label SXB at 4.5 g/night and titrated in 1.5-g increments to 6, 7.5, or 9 g/night or down to 3 g/night, based on individual clinical response. Treatment was 12 weeks; safety was the primary outcome. Efficacy was evaluated using the Narcolepsy Symptom Assessment Questionnaire (NSAQ), a five-point scale ("much improved" to "much worse") that assessed changes from baseline in specific symptoms. Response was defined as "much improved" or "somewhat improved" overall at weeks 6 and 12. RESULTS: Of 202 patients, 171 (85%) completed treatment; final doses were 3 g (n = 5), 4.5 g (n = 29), 6 g (n = 80), 7.5 g (n = 66), and 9 g (n = 22). Adverse events (AEs) were reported in 114 patients (56%), serious AEs in five (2%). The most common AEs were nausea (10%), headache (7%), and dizziness (5%). Response rate was 92% at week 6 and 90% at week 12; most patients reported improvements in all individual symptoms. Overall, 60% of patients rated their symptoms at 12 weeks as "much improved," and this improvement was dose dependent. CONCLUSIONS: The SXB safety profile was consistent with parent trials. Ninety percent of patients reported improvements as measured by the NSAQ.

Associations between severity of motor function and nonmotor symptoms in Parkinson's disease: a post hoc analysis of the RECOVER Study.

BACKGROUND: RECOVER (NCT00474058), a double-blind, placebo-controlled trial in patients with Parkinson's disease (PD) and unsatisfactory early-morning motor symptom control, demonstrated significant improvements with rotigotine in early-morning motor function (Unified Parkinson's Disease Rating Scale [UPDRS] III), and nocturnal sleep disturbances (modified Parkinson's Disease Sleep Scale [PDSS-2]), and improvements in nonmotor symptoms (NMS; Non-Motor Symptom Scale [NMSS]). METHODS: Post hoc analyses investigated the correlation between motor symptom and NMS severity in PD by evaluating associations between UPDRS III and both NMSS and PDSS-2 scores. Categories were defined for UPDRS III, NMSS, and PDSS-2 total scores; analyses were conducted for the full analysis set (n = 267). RESULTS: There was a trend toward increasing PDSS-2 and NMSS total and domain scores with increasing UPDRS III category at baseline and end of maintenance (EoM). Pearson correlation coefficients between UPDRS III and both NMSS and PDSS-2 total and domain scores were r = 0.12-0.44 (r(2) = 0.01-0.19) at baseline, r = 0.05-0.38 (r(2) = 0.00-0.14) at EoM, and r = -0.02-0.36 (r(2) = 0.00-0.13) for change from baseline to EoM. CONCLUSION: There was only a small correlation between severity of early-morning motor symptoms and overall burden of NMS and nocturnal sleep disturbances in RECOVER, suggesting that motor symptoms and NMS originate, at least partly, from distinct pathophysiological pathways.

Disrupted nighttime sleep in narcolepsy.

STUDY OBJECTIVES: Characterize disrupted nighttime sleep (DNS) in narcolepsy, an important symptom of narcolepsy. METHODS: A panel of international narcolepsy experts was convened in 2011 to build a consensus characterization of DNS in patients with narcolepsy. A literature search of the Medline (1965 to date), Medline In-Process (latest weeks), Embase (1974 to date), Embase Alert (latest 8 weeks), and Biosis (1965 to date) databases was conducted using the following search terms: narcolepsy and disrupted nighttime sleep, disturbed nighttime sleep, fragmented sleep, consolidated sleep, sleep disruption, and narcolepsy questionnaire. The purpose of the literature search was to identify publications characterizing the nighttime sleep of patients with narcolepsy. The panel reviewed the literature. Nocturnal sleep can also be disturbed by REM sleep abnormalities such as vivid dreaming and REM sleep behavior disorder; however, these were not reviewed in the current paper, as we were evaluating for idiopathic sleep disturbances. RESULTS: The literature reviewed provide a consistent characterization of nighttime sleep in patients with narcolepsy as fragmented, with reports of frequent, brief nightly awakenings with difficulties returning to sleep and associated reports of poor sleep quality. Polysomnographic studies consistently report frequent awakenings/arousals after sleep onset, more stage 1 (S1) sleep, and more frequent shifts to S1 sleep or wake from deeper stages of sleep. The consensus of the International Experts' Panel on Narcolepsy was that DNS can be distressing for patients with narcolepsy and that treatment of DNS warrants consideration. CONCLUSIONS: Clinicians involved in the management of patients with narcolepsy should investigate patients' quality of nighttime sleep, give weight and consideration to patient reports of nighttime sleep experience, and consider DNS a target for treatment.

Parkinson's disease and sleep/wake disturbances.

Parkinson's disease (PD) has traditionally been characterized by its cardinal motor symptoms of bradykinesia, rigidity, resting tremor, and postural instability. However, PD is increasingly being recognized as a multidimensional disease associated with myriad nonmotor symptoms including autonomic dysfunction, mood disorders, cognitive impairment, pain, gastrointestinal disturbance, impaired olfaction, psychosis, and sleep disorders. Sleep disturbances, which include sleep fragmentation, daytime somnolence, sleep-disordered breathing, restless legs syndrome (RLS), nightmares, and rapid eye movement (REM) sleep behavior disorder (RBD), are estimated to occur in 60% to 98% of patients with PD. For years nonmotor symptoms received little attention from clinicians and researchers, but now these symptoms are known to be significant predictors of morbidity in determining quality of life, costs of disease, and rates of institutionalization. A discussion of the clinical aspects, pathophysiology, evaluation techniques, and treatment options for the sleep disorders that are encountered with PD is presented.

Sodium oxybate reduces pain, fatigue, and sleep disturbance and improves functionality in fibromyalgia: results from a 14-week, randomized, double-blind, placebo-controlled study.

This 14-week, phase 3, double-blind, randomized, controlled trial evaluated sodium oxybate (SXB) 4.5 and 6g per night versus placebo in patients with fibromyalgia (FM). SXB is the sodium salt of γ-hydroxybutyrate (GHB). GHB is an endogenous compound, synthesized from γ-aminobutyric acid (GABA) and found broadly in the central nervous system and body. Among 548 randomized patients, a ≥30% reduction in pain was experienced by 54.2% and 58.5% of patients treated with SXB 4.5 and 6g, respectively, versus 35.2% for placebo with a 100-mm Visual Analog Scale (VAS) (P<0.001 for both comparisons). Relative to placebo, both SXB doses significantly reduced fatigue (with a 100-mm VAS; P<0.001) and sleep disturbance (with the Jenkins Sleep Scale; P<0.001), and resulted in significant improvements in function as measured by the FM Impact Questionnaire (P=0.003 and P=0.001 for 4.5 and 6 g per night, respectively). On the Short-Form 36 Health Survey, SXB-related improvement was significant on the Physical, but not the Mental, Component Scale. The proportion of patients who reported a global improvement of "much" or "very much" better on the Patient Global Impression of Change was significantly greater in both SXB groups versus placebo (P<0.001). Headache, nausea, dizziness, vomiting, diarrhea, anxiety, and sinusitis were the most commonly reported adverse events, with an incidence at least twice that of placebo. These results expand the evidence from previous clinical trials suggesting that SXB is effective and safe in FM.

Sodium oxybate: a potential new pharmacological option for the treatment of fibromyalgia syndrome.

Fibromyalgia syndrome (FMS) is a common disorder, characterized by diffuse pain and tenderness, stiffness, fatigue, affective disorders and significant sleep pathology. A new set of diagnostic criteria have been developed which should make it easier for a busy clinician to diagnose the condition. US Food and Drug Administration (FDA) approved medications for the treatment of FMS have, for the most part, been geared to modulate the pain pathways to give the patient some degree of relief. A different kind of pharmacological agent, sodium oxybate (SXB), is described that is currently approved for the treatment of excessive daytime sleepiness and cataplexy in patients with narcolepsy. SXB, an endogenous metabolite of the inhibitory neurotransmitter gamma-hydroxybutyrate, is thought to act independently as a neurotransmitter with a presumed ability to modulate numerous other central nervous system neurotransmitters. In addition SXB has been shown to robustly increase slow wave sleep and decrease sleep fragmentation. Several large clinical trials have demonstrated SXB's ability to statistically improve pain, fatigue and a wide array of quality of life measurements of patients with fibromyalgia. SXB is not FDA approved to treat fibromyalgia.

Safety overview of postmarketing and clinical experience of sodium oxybate (Xyrem): abuse, misuse, dependence, and diversion.

STUDY OBJECTIVES: This study reviewed the cumulative postmarketing and clinical safety experience with sodium oxybate (Xyrem), a treatment approved for cataplexy and excessive daytime sleepiness in narcolepsy. Study objectives were to investigate the occurrence of abuse/misuse of sodium oxybate since first market introduction in 2002, classify cases using DSM-IV criteria for substance abuse and dependence, and describe specific characteristics of these cases. METHODS: We retrospectively reviewed postmarketing spontaneous adverse event (AE) reports from 15 countries for all cases containing reporting terminology related to abuse/misuse to determine its occurrence. All death cases independent of causality were reviewed to identify associated risk factors. RESULTS: Approximately 26,000 patients worldwide received sodium oxybate from first market introduction in 2002 through March 2008. Of those 26,000 patients, 0.2% reported > or = 1 of the events studied. These included 10 cases (0.039%) meeting DSM-IV abuse criteria, 4 cases (0.016%) meeting DSM-IV dependence criteria, 8 cases (0.031%, including 3 of the previous 4) with withdrawal symptoms reported after discontinuation of sodium oxybate, 2 confirmed cases (0.008%) of sodium oxybate-facilitated sexual assault, 8 cases (0.031%) of overdose with suicidal intent, 21 deaths (0.08%) in patients receiving sodium oxybate treatment with 1 death known to be related to sodium oxybate, and 3 cases (0.01%) of traffic accidents involving drivers taking sodium oxybate. During this period, approximately 600,000 bottles of sodium oxybate were distributed, and 5 incidents (0.0009%) of diversion were reported. CONCLUSION: Cumulative postmarketing and clinical experience indicates a very low risk of abuse/misuse of sodium oxybate.