Treatment of Excessive Daytime Sleepiness in Patients with Narcolepsy

The aim of this review is to discuss and summarize the main therapeutic strategies for the management of excessive daytime sleepiness (EDS) in patients with narcolepsy. An overview of novel therapies and potential future options are covered as well. First line treatments for EDS in narcolepsy patients include modafinil/armodafinil and sodium oxybate. Other options with a stimulant effect, such as methylphenidate and amphetamines are considered if the former do not control the symptoms. More recently, pitolisant (H3 receptor inverse agonist) was approved by the European Medicines Agency, and solriamfetol (dopamine and norepinephrine reuptake inhibitor) by the Food and Drug Administration, for the treatment of EDS in adult narcolepsy patients. Sodium oxybate was recently approved for EDS management in paediatric patients from the age of seven. Further studies involving the paediatric population are warranted to have solid evidence in the management of children with narcolepsy. Ongoing research of new molecules is based on several mechanisms of action (histamine antagonists/inverse agonists, GABA receptor modulators), and potential future strategies involve immunologic treatment and hypocretin-based therapies. Additionally to the wakefulness-promoting agents and stimulants classically used, other pharmacologic options have been recently approved for the treatment of EDS in Europe (pitolisant) and the US (solriamfetol). Emerging treatments are under development; newly developed wakefulness-promoting agents act via different mechanisms of action, whereas other forms of therapy are focused in the underlying hypocretin deficiency that characterizes narcolepsy type 1.