Abstract
Narcolepsy is a chronic, disabling neurologic disorder characterised by excessive daytime sleepiness (EDS) and, in up to 60% of patients, cataplexy. Treatments for narcolepsy are aimed at improving wakefulness (e.g. modafinil, armodafinil, stimulants), reducing cataplexy attacks (e.g. sodium oxybate, venlafaxine), and treating the symptoms of disturbed nocturnal sleep, sleep paralysis and sleep-related hallucinations (e.g. sodium oxybate). In general, medications that increase the release, or inhibit the reuptake, of norepinephrine or dopamine have wake-promoting effects and are useful in managing EDS, whereas medications that inhibit serotonin or norepinephrine reuptake have anticataplectic effects. Modulation of γ-aminobutyric acid B (GABA(B)) receptors or histamine H(3) receptors (H3Rs) has effects on both EDS and cataplexy. Pitolisant, an H3R antagonist, and solriamfetol, a dopamine and norepinephrine reuptake inhibitor, are the most recently approved treatments for EDS associated with narcolepsy in the European Union (pitolisant) and the USA (pitolisant and solriamfetol). Several new agents are being developed and tested as potential treatments for EDS and cataplexy associated with narcolepsy; these agents include novel oxybate formulations (once-nightly [FT218]; low sodium [JZP-258]), a selective norepinephrine reuptake inhibitor (AXS-12), and a product combining modafinil and an astroglial connexin inhibitor (THN102). This review summarises the mechanisms of action, pharmacokinetics, efficacy, and safety/tolerability of recently approved and emerging treatments for narcolepsy.