Sodium oxybate extended-release suspension (LUMRYZ™) in narcolepsy: a profile of its use

Sodium oxybate extended-release suspension (LUMRYZ™; hereafter referred to as sodium oxybate ER) represents a promising novel option for the treatment of narcolepsy. It is the first once-nightly sodium oxybate formulation to be approved in the USA for the treatment of cataplexy or excessive daytime sleepiness (EDS) in adults with narcolepsy. Sodium oxybate ER has a pharmacokinetic profile that supports a single bedtime dose. In a pivotal phase 3 trial, once-nightly sodium oxybate ER dose-dependently increased sleep latency during the daytime, reduced cataplexy and daytime sleepiness, and improved disrupted nighttime sleep (DNS) compared with placebo in patients aged ≥ 16 years with narcolepsy. These improvements were statistically significant and clinically meaningful. Most patients who switched from twice-nightly immediate-release sodium oxybate (hereafter referred to as sodium oxybate IR) to once-nightly sodium oxybate ER in an open-label extension/switching study preferred the once-nightly formulation. Once-nightly sodium oxybate ER was generally well tolerated, including over the longer term, with a tolerability profile consistent with that of twice-nightly sodium oxybate IR. Narcolepsy, a disorder of sleep-wake instability, is a lifelong condition characterized primarily by overwhelming and persistent daytime sleepiness. Other symptoms include sudden muscle weakness associated with strong emotions (cataplexy), disturbed nighttime sleep, sleep paralysis, and vivid hallucinations when falling asleep or when awakening. The standard of care for patients with narcolepsy has been sodium oxybate, which requires twice-nightly dosing. Patients take their first dose at bedtime and must then awaken 2.5–4 h later to take their second dose. A less burdensome once-nightly formulation, sodium oxybate extended-release suspension (LUMRYZ™; hereafter referred to as sodium oxybate ER), has been approved for the treatment of cataplexy or excessive daytime sleepiness in patients with narcolepsy. In a clinical trial, patients treated with once-nightly sodium oxybate ER were able to stay awake longer during the day, felt less sleepy in the daytime, had fewer cataplexy attacks, and had less disruption to nighttime sleep than placebo recipients. Sodium oxybate ER was generally well tolerated. Nausea, dizziness, bed-wetting, headache, and vomiting were the most common treatment-related adverse events. Thus, once-nightly sodium oxybate ER represents a promising new option for the treatment of narcolepsy.