Comparative efficacy of sodium oxybate versus placebo on improvement of nighttime sleep in adult patients with narcolepsy: A systematic review and meta-analysis

Background

Narcolepsy, a central hypersomnolence disorder, disrupts sleep regulation. Sodium oxybate, a CNS (central nervous system) depressant, is widely used as a treatment, but there are surprisingly very few rigorous studies comparing its effectiveness to placebo in adults.

Objectives

To measure the comparative efficacy of sodium oxybate at a dosage regimen of 9 g versus placebo in improving nighttime sleep quality, reducing nocturnal arousals and sleep stage shifts, and enhancing the overall refreshed nature of sleep in adult patients with narcolepsy.

Methods

The methodology included a literature review of PubMed, Cochrane, Scopus, Google Scholar, and Clinicaltrials.gov, retrieving 53 randomized controlled trials (RCT) after removing 14 duplicates. Four studies met the criteria for gauging the efficacy of sodium oxybate compared to placebo in the adult population with narcolepsy. The primary efficacy outcome was improved sleep quality, whereas secondary outcomes were reduced nocturnal arousals and sleep stage shifts with an overall refreshed sleep nature. Analyses used RevMan 5.3 software, and SMD (standardized mean differences) with 95 % CI (confidence intervals) were calculated. Risk and publication biases were measured with Cochrane risk of bias tools and Comprehensive Meta-Analysis Software. Evidence certainty was measured using GRADEpro.

Results

Four RCT involving 1079 participants were analyzed for said outcomes, and relevant forest plots were generated. Statistical analysis showed a substantial improvement in sleep quality [SMD = 0.74(95%Cl:0.53,0.95; p < 0.00001; I² = 0 %; (high certainty)] and refreshing nature of sleep [SMD = 0.81(95%CI:0.51,1.11; P < 0.00001; I² = 0 %; (moderate certainty)], reduction in nocturnal arousals [SMD = −0.62(95%CI: 0.92,-0.32; p < 0.00001; I² = 0 %; (moderate certainty)] and sleep stage shifts [SMD = −1.22(95%CI: 1.46,-0.98; p < 0.00001; I² = 0 %; (high certainty)]. The risk of bias was located high for one study. Symmetrical funnel plots and Egger's regression intercepts testified to no significant publication bias.

Conclusions

The results showed that sodium oxybate considerably improved the quality of nocturnal sleep, resulting in substantial restorative advantages as well as a decrease in nocturnal arousals and sleep stage transitions. Significant results with low heterogeneity and p-values <0.05, showing consistent effects, were obtained from the analysis. However, overall reliability may be impacted by a high risk of bias in one study.