Sodium oxybate for narcolepsy with cataplexy: systematic review and meta-analysis.

University Sleep Disorders Center, King Saud University, Riyadh, Saudi Arabia.
Journal of clinical sleep medicine: JCSM: official publication of the American Academy of Sleep Medicine (Impact Factor: 2.93). 01/2012; 8(4):451-8. DOI: 10.5664/jcsm.2048
Source: PubMed

ABSTRACT To assess the efficacy and safety of sodium oxybate (SXB) in narcolepsy-cataplexy patients.
Systematic review and meta-analysis.
Adults with narcolepsy-cataplexy.
Electronic databases (e.g., MEDLINE) and references of included studies were searched to identify randomized controlled trials (RCTs) assessing the efficacy and safety of SXB for patients with narcolepsy-cataplexy. Risk of bias was appraised using the Cochrane risk of bias tool. Meta-analysis was conducted in Review Manager Version 5. Six RCTs and 5 companion reports were included after screening 14 full-text articles and 483 citations. All were private-industry funded. SXB (usually 9 g/night) was superior to placebo for reducing mean weekly cataplexy attacks (n = 2 RCTs, mean difference [MD]: -8.5, 95% CI: -15.3, -1.6), increasing maintenance wakefulness test (MWT) (n = 2, MD: 5.18, 95% CI: 2.59-7.78), reducing sleep attacks (n = 2, MD: -9.65, 95% CI: -17.72, -1.59), and increasing Clinical Global Impression scores (n = 3, relative risk, RR: 2.42, 95% CI: 1.77-3.32). SXB did not significantly increase REM sleep versus placebo (n = 2, MD: -0.49, 95% CI: -3.90, 2.92). Patients receiving SXB had statistically more adverse events versus placebo, including nausea (n = 3, relative risk [RR]: 7.74, 95% CI: 3.2, 19.2), vomiting (n = 2, RR: 11.8, 95% CI: 1.6, 89.4), and dizziness (n = 3, RR: 4.3, 95% CI: 1.1, 16.4). Enuresis was not significantly different from placebo (n = 2, RR: 2.6, 95% CI: 0.8, 9.8). All meta-analyses had minimal statistical heterogeneity (p-value > 0.1).
Narcolepsy patients on SXB have significant reductions in cataplexy and daytime sleepiness. SXB is well tolerated in patients with narcolepsy, and most adverse events were mild to moderate in severity.

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    ABSTRACT: Objective To analyze the acute effects of sodium oxybate (SO) on polysomnographic night-time (PSG) and multiple sleep latency test (MSLT) of patients with narcolepsy with cataplexy (NC). Methods Sixteen NC adult patients were recruited, together with 16 normal controls. Two consecutive PSG followed by two MSLT sessions were carried out, before and during the first night of SO assumption, respectively. Results The administration of SO was followed by a significant decrease in number of stage shifts and awakenings, wakefulness after sleep onset, percentage of sleep stage 1. Sleep efficiency and slow wave sleep percentage increased. REM latency decreased significantly from 73 to 12 min. Cyclic alternating pattern (CAP) rate remained unchanged but the percentage of CAP A3 subtypes decreased. The number of CAP A3 subtypes per hour of NREM sleep decreased significantly, whereas that of A1 remained unchanged. The duration of A1 and A3 subtypes was slightly increased. Chin muscle tone was not modified by SO as well as periodic leg movements during sleep, but their periodicity index decreased, becoming similar to that of controls. MSLT sleep latency also significantly improved after SO intake. Conclusions The administration of SO in NC patients is followed by immediate important and complex effects on PSG parameters and MSLT, including an evident (over)increase in slow wave sleep, which does not display a physiological microstructure, a moderate decrease in periodic and isolated LMs, possibly mediated by a disinhibited dopaminergic neuronal activity, and an improvement on daytime mean sleep latency at the MSLT.
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