The use of sodium oxybate to treat narcolepsy

Abstract

Narcolepsy is a life-long neurodegenerative disorder that causes considerable impairment to quality of life. Until the 1970s, the treatment for one of the main symptoms, excessive daytime sleepiness, was restricted to stimulants, whereas the second core symptom, cataplexy, was treated with antidepressants, and the resultant fragmented night-time sleep with hypnotics. Sodium oxybate (Xyrem^®, UCB Pharma, Brussels, Belgium) is an efficacious drug for all three symptoms which improves the quality of life of narcoleptic patients. Owing to its metabolic pathway, there is very little pharmacokinetic interaction with other drugs. In combination with modafinil, some of its therapeutic benefits are enhanced. Adverse events and side effects are moderate when taken according to indication and as recommended. Essential limitations have to be considered before starting the treatment (sleep-related breathing disorders, alcohol intake, hypnotic and sedative comedication, and epilepsy). This article gives an overview of sodium oxybate, which has been US FDA approved for the treatment of cataplexy and excessive daytime sleepiness in patients with narcolepsy, and EMA approved for the treatment of narcolepsy–cataplexy.

Keywords::

• cataplexy
• excessive daytime sleepiness
• flip–flop switch
• GABA
• narcolepsy
• sodium oxybate

Financial & competing interests disclosure

G Mayer has participated in advisory boards (narcolepsy, RLS) of UCB, Genzyme and sanofi-aventis. He received speaker’s honoraria from Cephalon, sanofi-aventis, Genzyme, Lundbeck, Takeda and UCB and was the recipient of research support from Cephalon and UCB. He participated in the International Xyrem studies SXB-15 and SX-22 (Orphan Drugs). The author has no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.