Lumryz (sodium oxybate for extended-release oral suspension)

A powder mixed with water and taken once at bedtime for cataplexy or excessive daytime sleepiness in people 7 years and older with narcolepsy. It is an extended-release form of sodium oxybate, the active ingredient in Xyrem, so a single dose lasts the night instead of 2 doses. The FDA approved it for adults on May 1, 2023 and for children 7 and older on October 16, 2024. It carries a boxed warning for slowed breathing and dulled alertness and for abuse and misuse, is a Schedule III controlled substance and is available only through its own REMS program. Alkermes has sold it since buying its developer, Avadel, in February 2026.

Narcolepsy type 1 is caused by the loss of brain cells that make orexin (also called hypocretin), a chemical messenger that keeps people awake and stabilizes muscle tone, which leads to daytime sleepiness, cataplexy (sudden muscle weakness set off by strong emotions) and broken nighttime sleep. Sodium oxybate is the sodium salt of gamma-hydroxybutyrate (GHB), which acts on GABA-B receptors that calm nerve activity. The label says it is thought to work during sleep through those receptors, but how it improves symptoms is unknown. Lumryz releases part of the dose right away and the rest over time, which lets a single bedtime dose cover the night^[1].

Lumryz has a boxed warning. It slows the brain and breathing, and dulled alertness and slowed breathing may occur at recommended doses. It is the sodium salt of GHB, and illegal GHB abuse has been linked to seizures, slowed breathing, coma and death, so Lumryz is available only through the LUMRYZ REMS program. The label says it must not be combined with alcohol or sedative sleep medicines, and other drugs that slow the brain, such as opioids and benzodiazepines, raise the risk of dangerous breathing problems. The label also says people should not drive or do hazardous work for at least 6 hours after a dose. In the adult trial, the most common side effects were nausea (up to 8% against 3% on placebo), dizziness (up to 6% against 0%), bedwetting (up to 9% against 0%), headache (up to 7% against 6%) and vomiting (up to 6% against 2%). Side effects led 15.9% of people on Lumryz to stop, against 1.9% on placebo, most often for dizziness. Lumryz itself was not studied in a children's trial; in the children's trial of immediate-release sodium oxybate, the most common were nausea (20%), bedwetting (19%), vomiting (18%) and headache (17%). Other warnings cover depression and suicidal thoughts, confusion and anxiety, sleepwalking and high sodium, about 1640mg at the 9g dose^[1].

A single packet is mixed with about 1/3 cup (80mL) of water and taken once at bedtime, at least 2 hours after eating, within 30 minutes of mixing. People take it in bed and lie down right away; most fall asleep within 15 minutes. Adults start at 4.5g once a night and go up by 1.5g a night each week to 6g to 9g once a night; doses above 9g have not been studied. Children 7 and older weighing 45kg or more follow the adult steps. Children under 45kg start on another sodium oxybate product, because the Lumryz strengths cannot give their starting dose, with maximums of 6g at 20kg to under 30kg and 7.5g at 30kg to under 45kg once on Lumryz; the label has no dose for children under 20kg. People switching from twice-nightly oxybate move to the nearest equivalent total nightly dose. Lumryz is not started in people with liver impairment, because the available strengths cannot give the lower starting dose. Packets come in 4.5g, 6g, 7.5g and 9g^[1].

Yes, Sodium oxybate for extended-release oral suspension (Lumryz) is FDA approved (2023) for the treatment of Narcolepsy Type 1.