LAUSR

Sodium oxybate (SXB) is strongly recommended for treatment of narcolepsy. Patients treated with available immediate-release oxybates are required to awaken for a second dose 2.5–4 hours after the bedtime dose to cover a full night of sleep. This study characterized SXB treatment patterns and discontinuation in narcolepsy patients. Mayo Clinic patients from 1975–2020 were identified using an electronic health record–based search. Patients with ≥1 narcolepsy-specific ICD-9/-10 code and ≥1 diagnostic mention of narcolepsy in clinical notes (identified using a natural-language-processing [NLP] algorithm) were included. NLP was used to identify SXB non-use events with manual chart reviews performed to characterize reasons for discontinuation, switching, or missing the second dose and effects of missing the second dose. Of the patients with narcolepsy prescribed SXB (n=351; mean age at first diagnosis code observed at Mayo Clinic, 32 y [IQR: 23.2–46.1]; 65.5% female; 92.3% white), 113 (32.2%) had clinical notes indicating discontinuation of SXB, with 71 (20.2%) including reasons for discontinuation. The most common reasons for discontinuation (n≥5) included lack of efficacy (n=11), side effects (n=10), gastrointestinal side effects (n=10), neurological side effects (n=9), psychiatric side effects (n=8), lack of access (insurance/cost, n=10), and resolution/absence of cataplexy (n=5). Mentions of switching from SXB to other drugs (n=12 patients) included switching to stimulants (mixed amphetamine salts, n=3; dextroamphetamine, n=2; methylphenidate, n=1), sedative hypnotics (zolpidem, n=2), antidepressants (mirtazapine, n=1), and wake-promoting agents (solriamfetol, n=1). Of the 38 patients (10.8%) with mentions of missing the second nightly SXB dose, reasons were recorded for 24 (63.2%), including inability to wake up (n=14), forgetting the second dose (n=3), and having to wake up early the following day (n=3). Consequences of missing the second dose were recorded for a small subset (increased cataplexy, n=4; lower daytime alertness, n=3; awakens earlier, n=1; tiredness, n=1). Limited data are available regarding real-world use of SXB. This novel study used a combination of NLP algorithm and manual chart review to identify difficulties patients have with the second, middle-of-the night immediate-release oxybate dose and patient-experienced consequences of not adhering to the prescribed dosing regimen. Avadel Pharmaceuticals