Characterization and treatment patterns of patients treated with immediate-release sodium oxybate for narcolepsy: A propensity score-matched cohort study

Background: Sodium oxybate (SXB) is strongly recommended for narcolepsy treatment. Comorbidities and treatment patterns of patients with narcolepsy treated vs not treated with SXB are unknown. Methods: An electronic health record-based search identified first-time Mayo Clinic patients with > 1 narcolepsyspecific International Classification of Diseases 9th/10th Revision code and > 1 diagnostic mention of narcolepsy in clinical notes (1975-2020). Common comorbidities were compared between age/sex matched cohorts with and without SXB treatment using odds ratios. Reasons for SXB therapy not being continued or taken as directed were identified using manual chart review. Results: Of the 4387 patients with narcolepsy identified, 8 % (n = 351) received SXB treatment and 92 % (n = 4036) did not. The most common comorbidities (>20 % overall population) were insomnia, fatigue, depression, hypertension, hyperlipidemia, obstructive sleep apnea, diabetes mellitus, arrhythmia, and idiopathic hypersomnia. In the cohorts of 351 matched patients, no significant differences between cohorts were observed for any comorbidity at any time point (overall, 5 years before or after diagnosis). Among patients who received SXB, 113 had clinical notes indicating discontinuation of SXB, with a reason documented for 71 (most common: lack of efficacy [n = 11]). Of the 24 recorded reasons for patients missing the second nightly SXB dose, the most frequent was the inability to wake up, with consequences noted the next day of increased symptoms. Conclusions: No significant differences in comorbidities were observed between cohorts. Although SXB is a highly effective treatment for narcolepsy, this study highlights challenges patients face while taking twice-nightly SXB, which may result in underuse/misuse and suboptimal treatment.